Three persons were killed and five others injured on Friday in a suicide bomb attack at Marriot hotel in Islamabad, where the Indian High Commission planned to hold a Republic Day reception later in the evening.
Pakistan's Interior Minister Aftab Khan Sherpao told the media here that a suicide bomber trying to enter the five-star hotel through the emergency exit blew himself up, also killing a security guard.
He said two persons were killed while TV channels here maintained three persons died in the explosion. Five others were injured.
Some vehicles in the car parking area were damaged.
Media reports here said two security guards and a suicide bomber were killed in the blast. The hotel has begun evacuating the guests to other places.
Meanwhile, private ARY TV reported that several journalists were injured when police lathi-charged newspersons covering the incident.
This is the second blast in the hotel in as many years.
The explosion prompted the government to declare a "red alert" in Islamabad, as also in sensitive cities like Karachi and Peshawar.
Pakistani security officials were not certain about the cause of the explosion.
While the Republic Day reception was due to be held in the hotel between 7 and 9 pm IST, Pakistan is also under heightened alert ahead of Muharram to prevent any sectarian tensions between Shia and Sunni extremist groups.
The attack occurred just around the Friday prayers.
President Pervez Musharraf has condemned the blast and ordered an inquiry into the incident.
The exit point of the hotel, where the explosion took place, was badly damaged. The bodies of the bomber and that of the guard who was killed trying to stop him from entering were still lying under the debris.
A large posse of police force was deployed in and around the Marriot hotel, where an explosion took place in 2004 when a high-level American delegation was staying there.
It was later stated that the blast had occurred due to high accumulation of gas in the lobby.