Four people have been killed in a suicide bomb attack outside the home of a member of Pakistan's ruling coalition, officials have said.

Asfandyar Wali Khan, head of the Awami National Party (ANP), was not injured in the Thursday’s attack outside the guest room of his home in the northwestern town of Charsadda, ANP officials said.

"Four people were killed in the suicide blats. The target was Asfandyar Wali but he is safe," Mian Iftikhar, the information minister for Pakistan’s North West Frontier Province (NWFP), said.

Members of the ANP, a party popular with ethnic Pashtuns, have been attacked on several occasions by fighters linked to the Taliban.

'Bomber shot'

The attack on Khan's home came as the ANP leader visited a guest in the building during celebrations for the Muslim festival of Eid-al-Fitr, police and party officials said.

Malik Naveed, a provincial police chief, said that the bomber was shot by guards as he attempted to enter Khan’s house.

"The suicide bomber tried to pass from the security scanner avoiding a physical search. Two security guards grabbed him but he tried to get away," Naveed said.

"Then he was shot and as soon as he fell on the ground he blew himself up … We had made strict security arrangements and that is why the attacker could not cause more damage or casualties."

One of Khan's guards was killed in the attack, a senior ANP member told Dawn, a Pakistani television channel.

The ANP has been a member party within Pakistan's ruling coalition since the Pakistan People's Party (PPP) defeated parties allied to Pervez Musharraf, then president, in elections in January.

Khan is the chairman of the Pakistani parliament's foreign relations committee.