Islamic State (IS) militants have killed about 400 people since they stormed the ancient city of Palmyra in central Syria, media reported.

Most of those killed in the millennia-old oasis city were women and children, Xinhua news agency reported citing the official Syrian TV.

Last Wednesday, the IS militants took full control of the ancient city of Palmyra in central Syria.

Both the residential parts and the historic parts, which host 2,000-year-old monuments and temples, of Palmyra have fallen into the hands of the IS, according to a London-based monitoring group.

An airbase, a central prison and the intelligence headquarters are all in IS hands now, said the group.

The IS offensive against Palmyra started on May 13. The group has since captured the towns of Sukhneh and Amiriyeh and the al-Hail and Arak oilfields.

Mamoun Abdulkarim, general director of Syrian antiquities and museums, told Xinhua that government forces managed to transport all movable ancient items from Palmyra to safe areas.

Abdulkarim expressed grave concern over the fate of the old temples and monuments that cannot be moved.

Palmyra, a Unesco World Heritage site, contains monumental ruins of a city that was one of the most important cultural centres in ancient times.