Smoke rises from Syrian city of Ras al-Ain following an attack from Turkey (Picture: PA).
Turkey recently launched an offensive in northern Syria, adding the violence in the Middle East nation during previous years.
However, Turkey is not the only country involved in the Middle East nation.
In March 2011, an uprising against the president of Syria, Bashar al-Assad, quickly turned into a full-blown civil war.
Millions of Syrian people were internally displaced and many are now international refugees.
The UK, meanwhile, has been flying an air campaign against members of so-called Islamic State (IS) in the country, since December 2015, as part of Operation Shader.
Recently, the US withdrew its troops from the north of the country, but a number of other military forces are involved in the region.
Here is what is happening in the country.
Bashar al-Assad's Syrian government is fighting the Syrian rebels following their uprising in the Arab Spring of 2011.
The president’s initial aim was survival, but it is now to return the entirety of Syria to government control.
Assad's forces struck up a deal with the Kurds to protect the north of the country, following the invasion of Turkish forces after the US announced its departure.
Turkey and Russia (allied with Syria) then agreed a deal to patrol the border there.
The Syrian rebels were trying initially to overthrow the Syrian government – now they are fighting for their survival in enclaves surrounded by Syrian government forces.
The Kurds are an ethnic group, living in areas across the Middle East, including in Syria and Turkey, but are seeking their own state.
The Turkish government, however, is opposed to the creation of an autonomous state in Syria as it believes the Kurds will use it as a launchpad for Kurdish opposition groups in eastern Turkey.
The Kurds have led the fight against IS, through their role in the Syrian Democratic Forces (SDF), together with the United States and coalition forces.
However, the announcement on 9 October, that US troops would withdraw from the region, led to a sense of betrayal.
They struck a protection deal with the Syrian government in the wake of Turkish military intervention in the north.
Kurdish forces under attack from Turkey in Syria began withdrawing from the border town of Ras al-Ayn, as part of a five-day ceasefire arrangement brokered by the United States.
Turkey was attempting to establish a 20-mile-deep "safe-zone" along the border, free of Kurdish fighters.
Turkey and Russia (allied with Syria) then agreed a deal to patrol the border there.
Daesh is another name for the so-called Islamic State (IS) - the terror group which created a caliphate in the Syrian power vacuum.
That caliphate has since been defeated, although the campaign to eradicate the group completely remains ongoing.
A former US military chief warned of a possible resurgence of IS, in the absence of American forces (following their withdrawal from Syria).
On 13 October, Kurdish officials reported hundreds of so-called Islamic State (IS) supporters escaped from a camp in Syria.
They said in a statement that 950 IS supporters escaped after attacking guards and storming the gates at the Ain Issa displacement camp.
It is home to around 12,000 displaced people, including nearly 1,000 foreign women with links to IS, plus their children.
On 22 October, Turkey agreed to a deal with Russia (allied with Syria) to patrol the border in northern Syria.
Turkey began an air and ground offensive there on 9 October, following the announcement American troops would leave.
Turkish forces had been hitting suspected Syrian Kurdish positions near a settlement in the north-east, according to reports.
UK Foreign Secretary Dominic Raab responded on 15 October by freezing Turkish export licenses for military items.
Turkey rejected an initial proposal from the US for a ceasefire.
US president Donald Trump announced sanctions on Turkey, but then announced he would lift them as a result of a ceasefire agreed between the two nations on 17 October.
Turkey claimed one of its soldiers was killed amid sporadic clashes with Kurdish fighters in northern Syria, despite the US-brokered deal, Turkey's defence ministry said.
The US President had previously threatened to "obliterate" Turkey's economy if the NATO members acted inhumanely, freezing trade negotiations with the nation and raising steel tariffs.
The Turkish government is opposed to allowing the Kurds to create an autonomous state in Syria as it believes the Kurds will use it as a launch pad for Kurdish opposition groups in eastern Turkey.
Turkey supported the Syrian rebel forces uprising in 2011.
US President Donald Trump announced on 24 October the ceasefire agreed with Turkey is 'permanent'.
He said sanctions previously announced in response to Turkish military intervention in northern Syria, would be lifted.
It followed the announcement on 9 October US troops would withdraw from northern Syria.
The departure drew criticism from some, who said America's absence would help to facilitate the return of Islamic State in the region.
Another key concern of the US military withdrawal from Syria is that Turkey could exploit the situation to attack the Kurds, which would be seen as a failure by the coalition to support its ally in the war against Daesh.
Following the announcement, Turkey began a military offensive in the north, which led to Donald Trump placing sanctions on Turkey.
The US House of Representatives voted overwhelmingly to condemn President Donald Trump's decision to withdraw troops.
A ceasefire was agreed between the two nations on October 17, to allow US-allied Syrian Kurds to withdraw, US Vice President Mike Pence announced.
It followed a previously rejected proposal.
A question has remained over where departing US troops will now go. US Secretary of Defense Mark Esper had expressed the intention for them to base themselves in western Iraq, detailing "two missions" - to protect Iraq and to perform a "counter-ISIS mission".
However, on 23 October, Iraqi defence minister Najah al-Shammari said they were only "transiting" Iraq and would leave within four weeks, heading either to Kuwait, Qatar or the United States.
The United States, as well as UK and other coalition partners, had assisted the predominantly Kurdish Syrian Democratic Forces with destroying Islamic State in Syria.
They also used ship-launched missiles and air strikes against Syrian government facilities when the Bashar al-Assad regime was suspected of carrying out chemical weapon attacks against Syrian opposition groups.
British Defence Secretary Ben Wallace said Britain wasn't consulted in the move to withdraw US troops from northern Syria.
British forces has been part of the fight against Daesh in the country, through its airstrikes in Operation Shader.
Prime Minister Boris Johnson met with NATO Secretary General Jens Stoltenberg in London on 15 October, where the pair discussed Turkey's military intervention and its possible consequences.
Foreign Secretary Dominic Raab called on the NATO member to exercise "maximum restraint and to bring an end to this unilateral military action."
"This is not the action we expected from an ally.
"It is reckless, it is counter-productive and it plays straight into the hands of Russia and indeed the Assad regime."
The UK, he said, "takes its arms export control responsibilities very seriously", adding that "in this case of course we will keep our defence exports to Turkey under very careful and continual review".
Russia agreed to a deal which will involve joint patrols with Turkey in northern Syria.
Russia has assisted the Syrian government primarily with air support, bombing Syrian rebel positions.
Iran opposes Daesh, who they claim carried out a terrorist bombing on a military parade in the southern Iranian city of Ahvaz in September 2018.
Iran retaliated by firing missiles from the country, over Iraq into Southern Syria.
The Iranians are also seeking to supply the Islamic military organisation Hezbollah in Lebanon with advanced missile systems, via Syria.
Iran has a stated aim of overthrowing the Jewish government in Israel.
Israel sees Iran as the main threat to its existence.
Israel has carried out strikes against Iranian forces in Syria as it considers them as a threat on its doorstep and does not want them strengthening Syrian or Hezbollah military capacity.
During raids on the Iranians in Syria, Israel also launched strikes against Syrian air defence systems.
Israel has occupied the Golan Heights in southwestern Syria since the Six-Day War in 1967.
NATO's Secretary General voiced "deep concern" about member state Turkey's military involvement in northern Syria and its potential consequences.
Jens Stoltenberg met with Prime Minister, Boris Johnson, at 10 Downing Street on 15 October.
They discussed Turkey's launching of an air and ground offensive, following the withdrawal of US troops on 9 October.
Mr Stoltenberg said, "I am deeply concerned about the consequences.
"Both when it comes to the fight against Daesh, human suffering, and stability in the wider region."
Asked about the suspension of arms sales to Turkey by member nations, he went on to say:
"It reflects that many NATO allies are very critical and are condemning the military operation in northern Syria."
The United Nations (UN) is investigating allegations Turkey has used chemical weapons against civilians in Syria.
A number of children have reportedly been treated for severe burns possibly from white phosphorus in the border town of Ras al-Ayn.
Turkey denies the claims.