Bombers on Friday killed 18 people in Afghanistan, a deadly start to President Hamid Karzai's second term that underscored spiraling insecurity nine years into the US-led war. A suicide bomber on a motorcycle struck the capital of the southwestern province of Farah, killing 15 people near the governor's home, while a roadside bomb killed three civilians in the east. The suicide bomber damaged buildings in Farah in an area where heavy trucks were being loaded, officials said. The bomber riding on a motorcycle detonated himself at a main square near my working office in my home, provincial governor Rohul Amin Amin told. Fifteen people have been killed, the governor said. Apart from a police officer, all the dead were civilians, Amin added. About 38 other people, mostly civilians, were wounded, officials said. More than a dozen of the wounded were in critical condition. Karzai condemned the brutal and unforgivable attack on civilians, said a statement from his office. In the eastern province of Khost, a roadside bomb ripped through a civilian car, killing three non-combatants, local police said. Four other people, all members of one family, were wounded in the blast, Gul Dad, a senior provincial police official, told. Four attacks have hit Afghanistan since Karzai was inaugurated. Two US soldiers and 10 civilians were killed in two separate bombings on Thursday. The attacks brought to 30 the number of people killed since Karzai was sworn in for another five years on Thursday, pledging to try to bring peace to the nation and take over security from foreign forces in five years. The insurgency against the Western-backed government is at its deadliest in the eight years since US-led troops ousted the Taliban, and is slowly encroaching into once peaceful parts of the north and west.