The Syrian army on Tuesday reached troops trapped for nearly three years by Isil fighters in the eastern city of Deir Ezzor, according to state-run media and a monitoring group, breaking one of the longest sieges of the Syrian civil war.

Around 100,000 residents have been holding out in the Syrian-government held half of the city, including the airport and an army base, since Islamic State of Iraq and the Levant (Isil) seized control of the area in 2014.

"The Syrian Arab Army has advanced on the Brigade 137 base front on the western side of Deir Ezzor city and broken the siege imposed by the Daesh organisation," state news agency SANA said, using the Arabic acronym for Isil.

A local journalist told AFP that flags had been raised throughout the government-held area in anticipation of the arrival of the soldiers, and that jubilant residents were greeting one another: “Good morning of victory”.