Three separate roadside bombs killed seven police and a government official in a spate of attacks around Afghanistan, officials said Saturday. A bomb in Khost province on Saturday killed the chief government official in Nadir Shah Kot district, said Wazir Pacha, spokesman for the provincial police chief. Militants fired at the official's car after the explosion, he said. Three others riding in the car, including one of the official's sons, were wounded, Pacha said. Elsewhere in Khost, another roadside bomb killed three border police on Friday, said Sher Ahmad Kochi, a police commander. In the south, a third roadside bomb hit a police vehicle and killed four policemen on Friday in Kandahar province, provincial police Chief Matiullah Khan Qatah said. Taliban militants frequently target Afghan police in their attacks. Police have less training and carry fewer weapons than the Afghan army or U.S. or NATO troops. Close to 900 police have died in militant attacks in each of the last two years. President Barack Obama has vowed to strengthen the U.S. focus on Afghanistan, where militants have increased attacks and expanded their reach in the last three years. Military officials are weighing sending up to 30,000 more American troops to bolster the 33,000 U.S. forces already in the country. Foreign troops are battling the Taliban and other militants and also supporting the government of President Hamid Karzai, who was elected after the 2001 U.S.-led invasion that ousted the Taliban's hard-line regime for sheltering top al-Qaida terrorist leaders.