Beirut: U.S.-led airstrikes targeted Syrian oil installations held by the militant Islamic State group overnight and early Thursday, killing nearly 20 people as the militants released dozens of detainees in their de facto capital, fearing further raids, activists said.
The latest strikes came on the third day of a U.S.-led air campaign aimed at rolling back the Islamic State group in Syria, and appeared to be aimed at one of the militants' main revenue streams. The U.S. has been conducting air raids against the group in neighboring Iraq for more than a month.
The Islamic State group is believed to control 11 oil fields in Iraq and Syria, and to earn more than $3 million a day from oil smuggling, theft and extortion. Those funds have supported its rapid advance across much of Syria and Iraq, where it has carved out a self-styled caliphate straddling the border, imposed a harsh version of Islamic law and massacred its opponents.
At least four oil installations and three oil fields were hit around the town of Mayadeen in the eastern province of Deir el-Zour, according to the Britain-based Syrian Observatory for Human Rights and two local activist groups. A third activist group loyal to the militants confirmed the reports. It wasn't immediately clear how important the refineries and fields were.
At least 14 militants were killed, said the Observatory, which gathers information from a network of activists on the ground. Another five people who lived near one of the refineries in the northeastern Hassakeh province were also killed, the Observatory said, adding that they were likely the wives and children of the militants.
Two activist collectives reported higher death tolls. Conflicting casualty figures are common in the chaotic aftermath of such events.
The planes came "with a terrifying sound and red lights before the explosions," one activist wrote, documenting each explosion.
The militants meanwhile freed at least 150 people from a prison in their de facto capital of Raqqa in northeastern Syria, fearing more strikes, according to activists there.
Other strikes hit checkpoints, compounds, training grounds and vehicles of the Islamic State throughout the territory they hold along the Euphrates River in northern and eastern Syria, with strikes hitting near the Turkish and Iraqi borders.
The raids targeted Syrian military bases seized by the Islamic State group, including the Brigade 93 and Tabqa bases. They also hit a building used as an Islamic court and a cultural center in the town of Mayadeen, the activists reported.
The Observatory said other airstrikes targeted the Nusra Front, a Syrian al-Qaida affiliate that has battled the Islamic State, and which is one of the most powerful groups fighting to overthrow Syrian President Bashar Assad. The strikes against the Nusra Front suggest a wider operation targeting other Syrian militants seen as a potential threat to the United States.
It was not immediately clear where the strikes against the Nusra Front took place.
The Observatory also reported airstrikes near a northern Kurdish area that Islamic State militants have been attacking for nearly a week now, causing the flight of over 150,000 people to neighboring Turkey. But it was not immediately clear who was conducting the airstrikes southwest of the area known as Kobani, or Ayn Arab.
A senior Kurdish fighter, Ismet Sheikh Hasan, said there were three airstrikes on the outskirts of Kobani overnight, but that fighters were not able to approach the area to see the target of the strikes.
Elsewhere in Syria, forces loyal to President Bashar Assad wrested back a rebel-held industrial area near Damascus after months of clashes, according to the Observatory and pro-Assad Lebanese media.
The pro-government forces seized the Adra industrial zone after rebels accused them of using chemical explosives on Wednesday. Footage of the wounded from the incident, in which six people were killed, showed men jerking uncontrollably and struggling to breathe before they died.