Damascus, Jul 6 (IANS): The Islamic State (IS) terror group has intensified attacks against the Syrian government forces in the country's eastern desert region, according to a war monitor.

Over the past 72 hours, 20 Syrian soldiers were killed and 25 others went missing as a result of the IS attacks in the desert near Sukhneh town, Xinhua news agency quoted the Syrian Observatory for Human Rights (SOHR) as saying on Sunday.

The UK-based watchdog group said 31 IS members were also killed, adding that group's attacks have spread from the countryside of Aleppo in northern Syria to the eastern province of Deir al-Zour.

Rami Abdul-Rahman, head of the Observatory, said the IS group has been active over the past few weeks in the desert of Sukhneh town and a triangle of countryside areas of Hama, Raqqa and Aleppo provinces.

The IS group is threatening the Damascus-Aleppo highway from the direction of the towns of Athria and Khanaser.

It also threatens the road between Deir al-Zour and the capital Damascus, according to the Observatory.

Abdul-Rahman said that IS has lost areas it controls but it's active in the desert and wants to send a message to the international community that it still exists.

When the group first expanded into Syria in April 2014, it had claimed nine Syrian province.