BEIRUT (Reuters) - The Syrian Observatory for Human Rights said the army repelled an Islamic State attack southeast of Aleppo on Thursday, after clashes temporarily cut a supply route linking the city to other government-held areas of Syria.

A Syrian military source denied earlier that the road was cut off and said there was no IS attack in the area. “On the contrary, the army is expanding its control in that area,” the source said.

The Observatory, a war monitoring group based in Britain, said fighting between Syrian government forces and IS militants southeast of Aleppo had blocked the Khanaser-Ithriya road, the government’s only supply route into the city.

The Syrian army and allied forces thwarted the attack and the road opened up again, the Observatory said. Islamic State militants did not make any new gains in the area, it said.

The road runs from Aleppo through the towns of Khanaser and Ithriya and links up with the cities of Hama and Homs further south.

It is the army’s supply route to Aleppo city, home to around 1.5 million people, which the government and its allies took full control of in December.