RAPPA, Syria, Aug. 25 (UPI) -- The Syrian government said Monday it was ready to work with United Nations-backed groups to fight Islamic State militants, after the Tabqa airbase on the Iraq-Syria border was seized.
IS controls territory on both sides of the border, attempting to establish a hardline Muslim caliphate. The strategic airbase fell to IS forces Sunday, according to the London-based Syrian Observatory for Human Rights, and Syrian state television said the base was evacuated.
Two other Syrian military bases in Raqqa province -- whose capital city of Raqqa is regarded as Islamic State's headquarters -- were previously overtaken. While the United States has conducted airstrikes against the IS over Iraq in the past month, it has stayed clear of Syrian territory. Syrian planes have bombed IS troops on its side of the border, but Syria lacks adequate ground assault capabilities.
Both sides sustained heavy losses in the fight for Tabqa, which began last week; the Observatory reported over 340 IS militants have been killed, as well as about 170 government military personnel. Photographs posted Sunday on the Internet showed IS forces standing amid a destroyed Syrian fighter jet, and the apparent beheading of a dead Syrian soldier.
Various rebel groups, including those who now comprise IS forces, have been fighting the Syrian government since 2011, with the country becoming a haven for trained opposition fighters.