Cairo, Aug 21 (IANS/EFE): Fierce clashes broke out Thursday between the Syrian army and militants of the Islamic State (IS) Sunni extremist group on the outskirts of al-Tabaqa military air base, the only bastion still in the hands of government forces in al-Raqa province in northern Syria, the Syrian Observatory for Human Rights (SOHR) said.

The SOHR said two cars driven by suicide bombers exploded near the base in the middle of the clashes, killing at least seven army personnel and an unknown number of jihadis.

The organisation, which has reported on the Syrian conflict since it began in March 2011, said government forces fired several Scud missiles, but did not mention if there were casualties.

Syrian aircraft also bombed at least one neighbourhood in the nearby town of al-Tabaqa, next to the base.

Last Sunday, at least 49 people were killed, including 31 IS members, in Syrian Air Force strikes in al-Raqa province, which is under the control of the jihadis.

The Sunni extremist organisation last June proclaimed an Islamic caliphate in areas it controls in Syria and Iraq.

More than 171,000 people have been killed since the conflict began in Syria more than three years ago, according to SOHR.