YPG Hasakah Syria
A YPG fighter raises a YPG flag over a barrier in Tel al-Aghbish village, which they retook control of from ISReuters

Kurdish YPG forces, backed by US-led coalition airstrikes, have claimed to have liberated the Islamic State (Isis) stronghold of Mabrouka in northeastern Syria.

If confirmed, the Kurdish victory would represent a serious setback for IS in the Hasakah region, after weeks of military defeats to the YPG forces.

Earlier, Iraqi Kurdish Rudaw news reported that Kurdish fighters imposed a siege on the strategic town of Mabrouka, which lies on a strategic road leading to the IS stronghold of Tel Abyad. After the liberation of Kobane in January, YPG fighters gained momentum in Hasakah in their bid to link the two regions in northern Syria. The Kurds' frontlines are separated by 90km of IS-held territory, according to local reports.

According to Kurdish Front Brigade spokesperson Ahmad Hasso, quoted by al-Akhbar news site, the YPG has received a "greenlight from the coalition" to keep fighting IS until the two Kurdish frontlines get connected.

On Tuesday (26 May), the US-led coalition carried out 10 airstrikes against IS positions, destroying checkpoints, weapons arsenal and armoured vehicles. A Kurdish fighter in the YPG told ARA news that the aerial bombings "help minimise our losses when we progress on the ground".

News of the liberation was announced on Twitter by Polat Can, head of the information centre of the Kurdish People's Protection Units (YPG).

The latest development came as IS made significant advances towards the Syrian capital Damascus despite intense airstrikes from Assad forces in and around the ancient city of Palmyra.

The London-based Syrian Observatory for Human Rights (SOHR), which relies on a network of local informants, said that the jihadists seized the Khnaifess phosphate mines and nearby houses. The phosphate mines sit about 70km (43 miles) south of Palmyra on a strategic highway that connects Palmyra (Tadmor in Arabic) and the capital.