DAMASCUS - The Syrian troops on Monday consolidated their positions at the surroundings of the ancient city of Palmyra in central Syria, following "ferocious" battles against the Islamic State (IS) militants, according to the state news agency SANA.

The Syrian forces fought intense battles against the IS group, whose militants attempted to attack military outposts in the vicinity of the ancient oasis city of Palmyra, a day after the terror-designated group withdrew from areas it had entered in the northern district of Palmyra.

Many IS militants were killed during the battles Monday, said SANA, adding that the government forces dealt heavy blows against the IS positions in the eastern countryside of Palmyra.

Sources told Xinhua that the IS militants fired multiple mortar shells on Palmyra on Monday, killing at least five people.

Meanwhile, the oppositional Syrian Observatory for Human Rights said as many as 167 Syrian soldiers and officers have been killed since the IS unleashed its attack against Palmyra on May 13. It said the death toll includes 18 Syrian officers from different ranks.

Mamoun Abdulkarim, Syria's director-general of antiquities and museums, told Xinhua that the IS militants withdrew from areas they entered in Palmyra on Sunday.

The Observatory, however, said the IS is still in control of the town of Amiriyeh and some areas in the northern countryside of Palmyra, as well as the al-Hail gas field at the outskirts of that ancient city.

Palmyra is considered one of the most important cultural sites in the Middle East. The ancient city contains the monumental ruins of a great city that was one of the most important cultural centers of the ancient world.