Scores of Kurds have fled their homes in the northern frontier region after four days of shelling by the Iranian army. Local officials said Turkey had also fired a number of shells into Iraqi territory.

Some displaced families have pitched tents in the valleys behind Qandil Mountain, which straddles Iraq's rugged borders with Turkey and Iran. They told the Guardian yesterday that at least six villages had been abandoned and one person had died following a sustained artillery barrage by Iranian forces that appeared designed to flush out guerrillas linked to the Kurdistan Workers Party (PKK), who have hideouts in Iraq.

Although fighting between Turkish security forces and PKK militants is nowhere near the scale of the 1980s and 90s - which accounted for the loss of more than 30,000 mostly Turkish Kurdish lives- at least 15 Turkish police officers have died in clashes. The PKK's sister party in Iran, the Kurdistan Free Life Party (Pejak), has stepped up activities against security targets in Kurdish regions. Yesterday, Kurdish media said eight Iranian troops were killed.

Rostam Judi, a PKK leader, claimed yesterday that no operations against Turkey or Iran were being launched from Iraqi territory. "We have fighters across south-eastern Turkey. Our presence in Iraq is purely for political work."

Frustrated by the reluctance of the US and the government in Baghdad to crack down on the PKK bases inside Iraq, Turkish generals have hinted they are considering a large-scale military operation across the border. They are said to be sharing intelligence about Kurdish rebel movements with their Iranian counterparts.

"We would not hesitate to take every kind of measures when our security is at stake," Abdullah Gul, the Turkish foreign minister, said last week.

There has been sporadic shelling of the region since May but officials worry that concerted military action against PKK bases in Iraq could alienate Iraqi Kurds and destabilise their self-rule region, one of few post-invasion success stories. Some analysts say Ankara and Tehran may be trying to pressure Iraq's Kurds, afraid that their de facto independent region would encourage their own Kurdish population.

Khaled Salih, the spokesman for the Kurdistan Regional Government in Irbil, said: "We condemn the shelling and urge the Iraqi government to demand the neighbours to respect our sovereignty."

Despite its support base in Turkey's impoverished south-east, the PKK is regarded by Ankara, Washington and the EU as a terrorist organisation. Mr Judi said the PKK was seeking a peaceful and democratic solution to the Kurdish issue in Turkey, and would welcome mediation from the US or Iraq's Kurdish leaders.

Last week, the Iraqi government said it had closed offices run by PKK sympathisers in Baghdad, and another office was shut by Kurdish authorities in Irbil.

The US is also to appoint a special envoy to find a solution to the PKK problem, but that may not be enough. Ilnur Chevik, editor of the New Anatolian newspaper in Ankara, said: "There is huge public pressure on the Turkish government to take action." But he doubted whether Turkish forces would mount a full-scale invasion."The build-up of troops is designed to say to the Americans and the Iraqis, the ball is in your court." Tehran was also taking advantage of the situation, he said, "to show Turkey that it was taking action against its shared enemy, while the US, Turkey's ally, has done nothing".