A suicide bomber struck at an election rally Saturday in northwestern Pakistan, killing 20 people and wounding 45, the latest in a string of attacks targeting politicians ahead of crucial parliamentary elections, official said. The blast went off inside a hall where about 200 supporters of the Awami National Party - a secular, ethnic Pashtun group - had gathered in the town of Charsadda in the turbulent North West Frontier province, where Islamic extremists operate. Mohammed Khan, a local police official, said two policemen were among the 20 dead. Four or five children were killed or wounded, he said. Abdul Waheed, 22, who suffered burns from the blast, told The Associated Press from his hospital bed in the nearby city of Peshawar that the bomb went off as an Awami National Party member was reciting verses from Koran, Islam's holy book. He said he did not see the bomber. "I only heard the blast and cries and then something hit me and I fell down," he said. TV footage of the aftermath showed the hall, located in the sprawling residence of a party activist, littered with bloodstained clothes, shoes, police caps and wrecked chairs. Khan said police had found the severed head of the suspected bomber. Interior Minister Hamid Nawaz said the attacker detonated his explosives "very close to the stage" where party officials were assembled. Afrasiab Khattak, the party's provincial leader and a prominent human rights champion, was addressing the rally but told Dawn television that he was not hurt. Nawaz said Islamic militants were threatening all the political parties in the northwest ahead of the Feb. 18 parliamentary elections. "They are against everyone," he told Dawn News TV. It was the third suicide attack targeting politicians in the Charsadda area in just eight months. In April 2007, a suicide bomber attacked a political rally by former interior minister Aftab Khan Sherpao, killing 28 people. Sherpao, who hails from a nearby village and was the top civilian security official in the outgoing government, was slightly injured. In December, a suicide bomber targeted Sherpao again amid hundreds of holiday worshipers at a mosque inside his home, killing at least 50 people. Sherpao was unhurt. Days later, opposition leader Benazir Bhutto was killed in a suicide attack in the northern city of Rawalpindi, an attack the government blamed on Taliban militant commander Baitullah Mehsud. Elsewhere Saturday, a roadside bomb wounded six paramilitary soldiers in southwestern Pakistan, local police official Allah Ditta said. The attack happened at Naushki, about 150 kilometers (90 miles) southeast of Quetta, the capital of southwestern Baluchistan province.