Turkey has bombed the main Kurdish rebel base in northern Iraq and chased rebels in a mountainous area in Turkey's south-east in response to attacks by the autonomy-seeking guerrillas.

The military said its warplanes had bombed at least 20 more suspected Kurdish rebel targets since late August, vowing to continue with its strikes. It gave no other details but the pro-Kurdish Firat news agency said the jets bombed the main rebel base on Qandil mountain deep inside northern Iraq on Wednesday.

About 2,000 Turkish troops, meanwhile, launched an operation against Kurdish rebels in the mountainous Tunceli province after a group of rebels was detected in the area, said CNN-Turk television. CNN-Turk said it was the largest anti-rebel operation in Tunceli, which is far from the Iraqi border.

The rebels, who are fighting for autonomy in Turkey from their bases in northern Iraq, have escalated attacks in recent months, killing dozens of members of the security forces and at least seven civilians since July. Suspicion also fell on Kurdish militants following Tuesday's car bomb explosion in Ankara that killed three people and wounded 34 others. No one has claimed responsibility, however, and Islamic and leftist militants are also active in Turkey.

Turkey is monitoring the movements of the rebels with Israeli-made Heron drones and also receives intelligence from US-operated Predator drones about rebel activities inside northern Iraq.

The military said it would launch air strikes whenever it pinpointed the rebel targets in northern Iraq. Turkish warplanes had already bombed 132 targets in August and Wednesday's announcement put the total number of targets that have been hit since the beginning of the campaign at 152.

In the latest reported violence in Turkey, suspected Kurdish rebels attacked a van carrying a group of civilian women, killing four, and separately killed a cadet at a police training school.

The attack on the women in Siirt occurred close to another police training school, leading to speculation that the assailants might have mistaken the van for a police vehicle. The women were on their way to celebrate with a friend who was leaving to start school in another province, said the provincial governor, Musa Colak.

Tens of thousands of people have died in the conflict since 1984.