Seven persons were injured on Thursday night when a major explosion rocked a five star hotel in the high-security zone in Islamabad, close to the residences of the Pakistan's president and prime minister, but the government ruled out terrorist involvement.

While local TV networks and the state-run PTV showed footage of widespread devastation, Information Minister Sheikh Rashid and Interior (Home) Minister Aftab Sherpao said the explosion was caused by short circuit and not by bomb. The two insisted that nobody was killed.

While Rashid appeared on the TV networks to deny that it was a bomb explosion Sherpao told the media at the damaged hotel premises, "There is no evidence of terrorist involvement. It is apparently caused short circuit."

The interior minister said an Italian was among the wounded. Doctors at a government hospital said seven people were injured in the blast.

The private Geo TV reported that the blast occurred at 9.35 pm (local time).

Police hurriedly cleared the place fearing a second explosion. Several ambulances rushed to the hotel to evacuate victims.

While the hotel was cordoned off by the police after the blast, PTV showed a badly damaged portico as well the lobby of the hotel located next to the PTV headquarters and a stone's throw from the parliament and prime minister's and president's offices.

Witnesses said the blast took place either in the lobby or outside. The hotel was full of people, majority of them foreigners, when the explosion took place. Droves of foreigners, including citizens of the UK, the US, China and Japan were seen leaving the hotel after the explosion.

A Geo TV reporter who visited the hospital where the injured have been admitted said six persons, including two foreigners, were brought for treatment. According to him, Sherpao confirmed that one of the injured was an Italian. The TV network said one of the injured suffered 90% burn injuries.

Inspector General of Islamabad Fia Guru said evidence from the scene pointed to a gas explosion but was at a loss to explain how it caused such extensive damage.

The five star hotel is located a stone's throw from the offices of prime minister and president besides the parliament and the blast is being seen as a major security lapse.

It followed intelligence reports that some vehicles with heavy explosives have been smuggled into the city by militants opposed to the policies of President Gen Pervez Musharraf.