KILIS, Turkey (Reuters) - Turkish artillery pounded Islamic State targets in northern Syria overnight and the U.S.-led coalition carried out air strikes, killing 28 militants near a Turkish border town repeatedly hit by rocket fire, Turkish military sources said.

Residents and Civil Defense members search for survivors from under rubble of damaged buildings after an air strike on the rebel held al-Saliheen district in Aleppo, Syria, March 11, 2016. REUTERS/Abdalrhman Ismail

The artillery strikes near Kilis, north of the Syrian city of Aleppo, started at about 8 p.m. (1700 GMT) and ended in the morning, the sources said. Intelligence reports had suggested the militants were preparing attacks, they said.

The air strikes destroyed a two-storey building used by the militants as a base, along with 11 fortified defensive positions, they said. The Turkish and coalition operations targeted an area about 10 km (6 miles) south of the border.

Turkey’s armed forces have stepped up attacks on Islamic State in Syria in recent weeks after rockets fired by the group repeatedly landed in Kilis, in what appeared to be a sustained and deliberate assault. More than a dozen hit the town last week alone.

Gunfire and occasional blasts from across the border could be heard on Wednesday from a hill in Kilis, which is home to more than 100,000 Syrian refugees.

Abdullah Karasu, a Kilis resident who works in a packaging firm, said he came to the hill every day to watch the action on the other side of the border, partly because it was a safer place to be than in the town center.

“I am not going to work anymore because the office is closed due to the rockets,” he said, standing with his son. Fewer rockets had landed in Turkey over the past three days, perhaps because of the military response, he said.

“But I doubt it’s finished ... This silence is ominous. It’s almost as unnerving as the rockets landing,” he told Reuters.

NATO member Turkey was initially a reluctant partner in the U.S.-led coalition fighting Islamic State and faced criticism in the earlier stages of the Syrian war for failing to stop foreign fighters crossing its borders and joining the militant group.

But it has suffered several attacks blamed on the radical militant group, including two suicide bombings in Istanbul this year. Those attacks targeted foreign tourists, killing a total of 16 people, most of them German and Israeli.

President Tayyip Erdogan said on Wednesday that Turkey’s armed forces had killed 3,000 Islamic State fighters in Syria and Iraq, where Turkish soldiers are training local forces to fight the insurgents. He did not give a time frame.