Islamabad  - A suicide car bomber on Sunday attacked a polling station in Pakistan's troubled North West Frontier Province, killing at least 30 people and wounding around 20, police said.

The bomber rammed his explosives-laden vehicle into the wall of a government school serving as a polling station in Shal Bande village located 10 kilometres from Dagar, the main town in Buner district.

The intense blast destroyed the school building and several nearby shops where different political parties contesting the by-polls on a National Assembly seat had set up their election camps, said Khan Ghalib, a subordinate of Buner police chief.

"So far 30 people have been confirmed dead, while 20 are injured," Ghalib said. A policeman and a man, who volunteered for security duty outside the polling station, were among the dead.

According to the official, many people were still feared buried under the rubble of collapsed structures, and the casualty figures could rise as more victims were pulled out of the debris.

Some of the injured admitted to the hospital in Dagar were in a critical condition.

The provincial information minister, Mian Iftikhar Hussain, confirmed that the attack was carried out by a suicide bomber to give a message that it was impossible to hold a peaceful election.

"We (the people of north-western region) facing a war-like situation in which such incidents can take place any time," Hussain told the Urdu-language Aaj television channel.

Pakistani leadership condemned the blast after which balloting was partially suspended in Buner which borders the militant-infested Swat district.

Government troops have been battling Taliban militants led by local radical cleric Maulana Fazlullah in Swat for several months, flushing out the rebels from some of the areas.

Media reports earlier said that elders in Buner also raised a traditional militia and killed a few intruding insurgents, coming in direct conflict with the militants.

The BBC news service reported that a Taliban spokesman claimed responsibility for the bombing, saying it was carried out "in retaliation for an attack on their fighters." (dpa)