Debris of a house following an alleged US-raid on the Syrian village of Barisha, after reports Abu Bakr al-Baghdadi died in the outskirts of the village (Picture: PA).
The so-called Islamic State group (also known as IS, ISIS and Daesh) still poses a threat, despite the death of its leader in a US special forces operation, experts have warned.
On Sunday, US President Donald Trump confirmed Abu Bakr al-Baghdadi had died in Syria.
Mr Trump said al-Baghdadi detonated a suicide vest after fleeing into a tunnel "whimpering and crying and screaming" as he was chased by military dogs.
However, experts say his death does not mean IS is any less of a threat.
Chris Costa, a former senior director for counter-terrorism for the National Security Council in the Trump administration, said: "The bottom line is: this puts the enemy on its heels, but the ideology - and this sounds so cliched - is not dead."
Mike Rogers, the ranking Republican on the House Homeland Security Committee in US congress, said five years of US and coalition efforts inside Syria have not eliminated the IS threat.
"While the death of its leader is a tremendous blow for the group, about 10,000 ISIS fighters remain in the region and will continue to carry out guerrilla attacks and seek new territory," he said.
Since 2014, British fighter jets have been targeting IS fighters in Iraq and Syria as part of Operation Shader.
The operation has been the RAF's most active operation of the past 25 years, with the UK being the second biggest contributor in the international coalition.
In March, it was announced IS' self-proclaimed "caliphate" in Syria had been defeated.
But according to defence officials in Iraq and Afghanistan, the group is growing in power and numbers outside of Syria.
Its affiliated groups are believed to be expanding into countries including Pakistan, Tajikistan, Iran, India, Bangladesh and Indonesia.
There were concerns that Mr Trump's decision to withdraw troops from north-east Syria earlier this month could lead to an IS resurgence.
Mr Trump, who often said Daesh was "100%" defeated, admitted it could make a comeback.
He said IS is "very, very strongly looking to build [itself] again".
The US President suggested that other countries, including Russia, should carry on the fight against IS.
He has long backed the withdrawal of American troops in the Middle East to end the "endless wars" started under his predecessors.
However, there is no indication that US forces will abandon the mission any time soon.
US Defense Secretary Mark Esper told ABC's This Week: "Our job is to stay on top of that and to make sure that we continue to take out their leadership."
Mr Trump said US forces had gathered "highly sensitive" material about IS in its operation on al-Baghdadi's compound in north-west Syria.
A UN official said he hoped the evidence seized could hopefully help future prosecutions of those accused of "heinous acts" committed in the name of IS.