Officials in the Ministry of External Affairs said the `hostile act,' coming in the wake of concerted attacks by Pakistani terrorists on Army camps in Jammu & Kashmir as well as the interdiction of Highway 31 linking the North-East with the rest of the country last night, denoted a `premeditated pattern of intrusion.'

Government officials said Prime Minister A B Vajpayee would not be calling Pakistan Prime Minister Nawaz Sharif tonight over the hotline, saying the `time was not appropriate' for such a call. Vajpayee was, however, being kept continually abreast of the situation.

India's ambassador to the US Naresh Chandra immediately alerted the US State Department about the incident and kept them informed as events unfolded through the day. Officials in Washington said they were worried about the `increase in tension' between the two countries but no stronger statement has since emerged from there.

The story about the incident was first broken to the international media by Islamabad and was described by Pakistani information minister Mushahid Hussain as `retaliatory' action for the shooting down of two Indian planes during the Kargil conflict.

He said a media party was immediately on its way to the site of the wreckage, which was within Pakistan.

Coming less than a month after the end of the Kargil conflict, where Pakistan was forced to withdraw under somewhat ignominious circumstances, the intrusion of the Pakistani jet is seen here as another attempt to `internationalise' a lesser-known dispute in the Indo-Pakistani relationship: the Sir Creek area, a marshy no-man's land just off the Rann of Kutch in Gujarat. Both countries lay claim to the area.

New Delhi's version of the shooting down is borne out by the fact that the wreckage has been located within Indian territory, short of the marshy terrain in an area called Kori Creek.

Pakistani foreign minister Sartaj Aziz, however, told journalists in Islamabad, that the plane was shot down by the IAF in the Sir Creek. Late in the evening in Delhi, Pakistani high commissioner Ashraf Jehangir Qazi was summoned by Foreign Secretary K Raghunath and told of the transgression of the Pakistani military aircraft, which violated the 1991 agreement on prevention of air space.

`Whatever has happened is entirely the responsibility of Pakistan, including the death of those who were in the aircraft,' the spokesman said.

Interestingly, a middle-level diplomat of the Pakistani high commission here called a ministry official at 4.15 pm to tell him that Pakistan had located the wreckage of a Pakistani naval aircraft, that had lost contact in the morning `close to the India-Pakistan border.'

The diplomat did not claim that the wreckage had landed within Pakistani territory, a clear contradiction to Aziz's claim that the aircraft was on a routine mission, had been shot down by the IAF and that the wreckage had landed 2 km within Pakistani territory.