Syria rebels push IS further back from Turkish supply route

A Syrian rebel alliance has pushed Islamic State group militants further away from one of its key supply routes from neighbouring Turkey, a monitoring group said on Saturday. 

The rebels ousted IS from the village of Al-Bal, which it captured on Tuesday, threatening the Bab al-Salama Turkey-Syria border crossing, just 10 km away, the Syrian Observatory for Human Rights said.

The village's recapture late on Friday came after heavy fighting which killed 14 rebels and 15 IS militants, Observatory director Rami Abdel Rahman said.

Further south, the two sides battled for the town of Marea, which lies on the road between the crossing and the rebel-held eastern sector of the main northern city of Aleppo.

"The ultimate goal for IS is to cut off this crossing," said Abdel Rahman.

Activists said the rebels were fighting to defend Marea, while simultaneously launching their own attacks on IS positions in the area. 

"IS is trying to surround the town by occupying the villages all around it," said Mamun Abu Omar, head of a local pro-rebel press agency.

The rebel alliance is fighting both IS and government forces in Aleppo province, which is one of the most complex battlegrounds of Syria's multi-front civil war.

In some areas, the alliance is supported by fighters of IS's rival, Al-Qaeda affiliate Al-Nusra Front.

On Thursday, news emerged that Nusra fighters had shot dead at least 20 Druze villagers in Idlib, despite assurances from Nusra's leader, Abu Mohammed al-Jolani, that the group would not target minorities.

IS fighters control areas in the province's east, and have been laying siege to the Kweyris military airport, still controlled by the government. 

Early on Saturday, three government officers were killed when their helicopter was shot down by IS just outside the airport, Abdel Rahman told AFP.

Meanwhile, Kurdish militia advanced further into IS's bastion province Raqqa, in Syria's north, in a bid to capture the key border town of Tal Abyad.

The Observatory said Kurdish People's Protection Units (YPG) had edged to within 10 km southwest of Tal Abyad, used by IS as a gateway from Turkey. 

Backed by airstrikes from a US-led coalition, Kurdish forces recaptured the flashpoint town of Kobane - which lies west of Raqqa province - from IS in January.