Syrian government forces and their Russian backers have completely recaptured the ancient city of Palmyra from so-called Islamic State (IS) militants, the two allies say.

The army and other pro-government forces were reported to have entered deep into the city after IS pulled out. It ends the second occupation of Palmyra by the jihadists.

The first time they controlled the area, the militants destroyed some of its most celebrated monuments.

IS fighters were driven out in March last year, but managed to retake the city, its world famous ruins and the surrounding area.

Syria’s Ambassador to the United Nations Bashar al-Jaafari confirmed the recapture on Thursday. He said the city had been “liberated from the hands of the terrorist organisation” and that President Bashar al-Assad had kept his promise to drive them out.

In Russia, Defence Minister Sergei Shoigu was reported by local media to have told President Vladimir Putin on Thursday that Palmyra had been fully retaken by the Syrian army with help from the Russian air force.

There were clashes and heavy shelling across the historic city as the offensive unfolded on Wednesday, UK-based monitoring group the Syrian Observatory for Human Rights said.

IS militants planted mines in several areas of the city before withdrawing, it said.

IS held the ruins and the nearby city, known locally as Tadmur, for 10 months after seizing it for the first time in May 2015. It blew up temples, burial towers and the Arch of Triumph, believing the shrines and statues to be idolatrous. The jihadists also destroyed the 2,000-year-old Temple of Bel, the great sanctuary of the Palmyrene gods.

Unesco World Heritage Site

Site contains monumental ruins of great city, once one of the most important cultural centres of the ancient world

Art and architecture, from the 1st and 2nd centuries, combine Greco-Roman techniques with local traditions and Persian influences

More than 1,000 columns, a Roman aqueduct and a formidable necropolis of more than 500 tombs made up the archaeological site

More than 150,000 tourists visited Palmyra every year before the Syrian conflict

The militants were then forced out by a Russian-backed government offensive in March 2016, but regained control while pro-government forces were focused on the battle for the city of Aleppo late last year.

In January, satellite images revealed that the group destroyed the tetrapylon – a group of four pillared structures which were mainly modern replicas – and part of the Roman Theatre. The head of Unesco, Irinia Bokova, described the destruction as “a new war crime”.