Armenia and Azerbaijan have accused each other of violating a new ceasefire in their ongoing conflict.
Hundreds of people have been killed in the clashes.
Heavy fighting between the two countries broke out on 27 September over the separatist region of Nagorno-Karabakh.
The latest truce, which came into force at midnight on Saturday, was the second attempt to establish a ceasefire since the fighting began.
The attacks mark the biggest escalation of conflict over the region in more than a quarter of a century.
On the day the ceasefire came into place Armenian military officials reported shelling and missile strikes by Azerbaijani forces, carried out overnight in the conflict zone.
Armenian Defence Ministry spokeswoman Shushan Stepanian said: “The enemy launched an attack in the southern direction” of the conflict zone, and there were “casualties and wounded on both sides”.
Azerbaijan’s Defence Ministry maintains that Armenian forces kept on shelling in the conflict zone overnight despite the ceasefire and then launched attacks in several directions the following morning.
The ministry also accused Armenia of using large-calibre weapons to attack the Azerbaijani army along the border between the two countries – in two regions north of Nagorno-Karabakh.
Armenian military officials deny this.
Nagorno-Karabakh lies within Azerbaijan but has been under the control of ethnic Armenian forces backed by Armenia since a war there ended in 1994.
The fighting has drawn worldwide concern recently because oil-rich Azerbaijan has new military weapons and the backing of Turkey.
Armenia claims Turkey is sending Syrian mercenaries into the fighting to help Azerbaijan.
Turkey denies this allegation.
Cover image: Rescue workers clear out the ruins of a residential house as they search for survivors after a military strike in Ganja, Azerbaijan (Picture: PA).