Sixteen people, including three civilians, have been killed in air strikes by the Syrian army against an eastern town which was captured by fighters from an al Qaida breakaway group a day earlier, according to activists.
The Britain-based Syrian Observatory for Human Rights said warplanes pounded Muhassan with six air strikes.
Fighters from the Islamic State of Iraq and the Levant (Isis) stormed the town along the Euphrates River yesterday.
The town is in the eastern province of Deir el-Zour, near the Iraqi border, where the Islamic State has been on the offensive since late April.
It came as militants from the group seized an Iraqi crossing on the border with Syria after a day-long battle in which they killed some 30 Iraqi troops.