A suicide bomber on Friday tried to storm a five-star hotel in Islamabad hours before a reception there by Indian High Commissioner Satyabrata Pal to mark the Republic Day, killing himself and a security guard and injuring seven others.

Unfazed by the attack, Pal went ahead to host this evening's reception at the Marriot hotel in the heart of the city, where Pakistan's Education Minister and former ISI chief Asharaff Jahangir Qazi was the chief guest.

Over a hundred guests, including top Pakistani officials, important personalities, members of the diplomatic corps and journalists attended the event.

President Pervez Musharraf, who himself has survived three assassination bids, strongly condemned the blast and ordered an immediate inquiry. Asserting Pakistan's unwavering commitment in the fight against extremists and terrorists, he said all-out efforts will be made to bring to book the perpetrators of the attack.

Interior Minister Aftab Khan Sherpao told media persons that a suicide bomber tried to enter the heavily protected hotel through the emergency exit.

When he was stopped by a security guard, he set off the explosives strapped to his body, killing himself and the security man, Sherpao said.

Earlier, television channels had reported that two guards were among the three persons killed in the blast. At least seven persons were injured in the explosion that also damaged several cars parked in the area. Some of the injured were in critical condition in the hospital.

Officials identified the dead security guard as Mohammad Tariq. No one has taken the responsibility for the attack, but Sherpao said the explosion was the work of 'anti-state elements who want to create unrest.'