U.S. coalition-led warplanes struck jihadis attacking a town near the Turkish border for the first time Saturday, as well as positions including wheat silos in the country's east, activists and a Kurdish official said.

The coalition, which began its aerial campaign against Islamic State fighters in Syria early Tuesday, aims to roll back and ultimately crush the extremist group, which has created a proto-state spanning the Syria-Iraq border. Along the way, the militants have massacred captured Syrian and Iraqi troops, terrorized minorities in both countries and beheaded two American journalists and a British aid worker.

Nawaf Khalil, a spokesman for Syria's Kurdish Democratic Union Party, or PYD, said some of the strikes targeted for the first time Islamic State group positions near the northern town of Kobani, also known as Ayn Arab. The town has been under attack by jihadis for days and Khalil said the strikes destroyed two tanks.

He said the town was later shelled by jihadis, wounding several civilians.

The Britain-based Syrian Observatory for Human Rights said the coalition's strikes near Kobani came amid heavy fighting between Islamic State fighters and members of the Kurdish force known as the People's Protection Units, or YPK. It said there were casualties among jihadis.

The activists had no immediate word on casualties from Saturday's strikes. The Observatory reported Friday that 13 civilians have been killed by the strikes since they began.

Kurdish fighter Majid Goran told the Associated Press by telephone from Kobani that two bombs were dropped over the village of Ali Shan, near Kobani at 6 a.m. (0300 GMT).

Goran said however, that the strikes were ineffective and that the positions hit "were empty."

Turkey's Dogan news agency reported Saturday that the sound of heavy fighting could be heard from the Turkish border village of Karaca. The agency said Kurdish forces retook some positions it had lost to the Islamic militants a few days ago. It did not cite a source for the report.

Dozens of people wounded in the fighting arrived in Turkey for treatment on Saturday, it said.

The Observatory said the strikes in the east targeted compounds for the Islamic State group in the central province of Homs and the northern regions of Raqqa and Aleppo. The group said 31 explosions were heard in the city of Raqqa, the group's de facto capital, and its suburbs.

The Local Coordination Committees, another activist group, said the strikes in the east hit the province of Deir el-Zour as well as Raqqa. The LCC also said the coalition targeted wheat silos west of Deir el-Zour city.

It was not immediately clear why the silos were targeted. Saturday's strikes came after two days of strikes by the United States and its Arab allies on a dozen makeshift oil-producing facilities in Deir el-Zour, trying to cripple one of the militants' primary sources of cash - black market oil sales that the U.S. says produce up to $2 million a day.

Near the capital Damascus, Syrian troops entered the once rebel-held northeastern suburb of Adra after days of clashes, Syrian state TV said. The advance came two days after troops captured the nearby Adra industrial zone.