The Turkish army has begun using Israeli-made unmanned aircraft to monitor Kurdish rebel movements in neighbouring Iraq, the Anatolia news agency reported Monday, quoting the army chief.

"In the past 10 days, we have started using our Heron systems... the surveillance systems we bought from Israel, in the north of Iraq," General Ilker Basbug said in Canakkale, northwestern Turkey, according to Anatolia.

The drones are being used "at a certain distance in the north of Iraq in coordination with the Americans," Basbug told reporters, adding that the aircraft were operated "by our own personnel."

There has been media speculation that the drones were idle because Israeli operators left Turkey amid the crisis between the two countries over Israel's May 31 raid on Gaza-bound aid ships, in which nine Turks were killed.

The Turkish army is fighting surging violence by the separatist Kurdistan Workers' Party (PKK), which uses rear bases in neighbouring northern Iraq as a launching pad for attacks against Turkish targets across the border.

Twelve soldiers were killed in PKK attacks over the weekend, most of them when rebels assaulted a border unit at the Iraqi frontier early Saturday.

Basbug played down suggestions that an intelligence failure had led to the attack, which prompted a Turkish air raid on PKK hideouts in Iraq.

The 2005 drone contract was part of an 185-million-dollar project that involved the manufacture of 10 aircraft, surveillance equipment and ground control stations by a joint venture led by Israel Aerospace Industries.

Turkey has received six aircraft and the delivery of the remaining four are expected in June or July, according to Turkish officials.