ISLAMABAD, May 26 (AFP) - Pakistani Foreign Minister Sartaj Aziz on Wednesday blamed India for raising border tensions in the disputed Kashmir region and said it violated a recent joint pledge to improve relations. "The escalation at the Line of Control (LoC, in Kashmir) is against the spirit of the Lahore Declaration," signed by Pakistani Prime Minister Nawaz Sharif and his Indian counterpart Atal Behari Vajpayee in February, he said. "We have called for restraint on both sides. We do not know why they (Indians) are escalating the situation," Aziz told reporters. Aziz spoke to journalists before reports from New Delhi said the Indian air force had launched strikes in the Kargil sector near the LoC to flush out alleged Moslem militants. Troops have been trading artillery fire for more than two weeks across the LoC, as Indian forces battle the guerrilas on Kargil heights. "We have just retaliated when our positions are attacked and we only defend ourselves," the foreign minister said, adding: "We will take all necessary measures. "We have defended our positions and at the same exercised restraint." He said Pakistan was ready in principle for expert level parleys and for talks at the level of ministers of state on exchange of civilian prisoners. The talks may take place in a few weeks in Islamabad, Aziz said.  