The major operation launched by the security forces against bases of the rebel Kurdish Workers Party (PKK) in northern Iraq on 20 March has been harshly criticised by European leaders and attacked in the US Congress. The operation, involving some 35,000 troops, has cast a cloud over Turkey's ties with the EU and prompted a leading US senator to propose a bill linking aid to human rights.

The operation aimed to secure the border region and eliminate suspected PKK bases accommodating about 2,400-2,800 guerrillas, according to Turkish officials. They said 200 PKK fighters were killed in the first two days of the offensive, for the loss of eight Turkish soldiers. Iraqi Kurdish groups said the operation, which included air attacks, resulted inheavy civilian casualties. Turkish press reports said the PKK groups appeared to have been alerted by the military build-up before the operation and had withdrawn to inaccessible areas. Turkey's last major incursion into Iraq was in 1992.

French Foreign Affairs Minister Alain Juppe said on 21 March that the operation was inconsistent with Turkey's duty to abide by basic principles of legality and human rights as an EU associate member, and a member of NATO and the Council of Europe. France is the current EU president.

Only a fortnight previously, Juppe had championed Turkey's entry - against Greek opposition - into a customs union with the EU. A meeting of the Turkish-EU Association Council agreed upon the terms of Turkey's entry on 6 March.

The European parliament itself has made its assent to the customs union conditional on improvements in Ankara's human rights record, particularly over the Kurdish issue. Juppe, along with the German and Spanish foreign affairs ministers, was due in Ankara for a one-day visit on 23 March to discuss the customs union and related issues.

US President Clinton had expressed his understanding of Turkey's need to deal decisively with the PKK during a telephone conversation with Prime Minister Tansu Ciller, a US administration spokesman said on 20 March. She assured Clinton the operation would be limited in duration, the spokesman added. However, the US did not condone the operation, said a US State Department spokesperson on 21 March.

A more robust reaction came from Senator Alfonse D'Amato, chairman of the Banking Committee. He has introduced a bill stating that Turkey must cease military action against the Kurds, recognise Kurdish rights and withdraw its forces from northern Cyprus, otherwise it will receive no US aid in the year starting 1 October. In introducing the bill on 21 March, he said: 'The simple truth is that Turkey is run by a group of thugs who systematically abuse the human rights of its own citizens and those of neighbouring nations as cruelly and viciously as the world's most tyrannical regimes.'