KHOST, Afghanistan (Reuters) - Three suicide bombers killed 20 people in an attack on a construction firm in a restive province in southeastern Afghanistan, government officials said Monday, with the Taliban claiming responsibility for the assault.
Violence across Afghanistan has spiraled in the past year, with Taliban-led militants stepping up their fight against the Afghan government and its Western backers as Kabul prepares to take over responsibility for security gradually from foreign forces.
An Interior Ministry statement said the attackers forced their way into the firm's compound after killing a security guard and then detonated a truck packed with explosives.
"As a result, 20 employees of the construction company were killed and 50 others were injured," the statement said.
Mohebullah Sameem, governor of southeastern Paktika province, earlier put the death toll from the attack in the remote Bermel district at 13.
He said the dead and wounded included employees of the firm and other civilians. Construction crews and others working on infrastructure projects are frequently targeted by insurgents.
Bermel shares a long border with lawless areas of neighboring Pakistan, where insurgents are said to have safe havens from which they launch attacks inside Afghanistan.
In an emailed statement to media, Taliban spokesman Zabihullah Mujahid claimed the Islamist group had carried out the attack but said it had been on a military base and that 49 foreign and Afghan troops had been killed and wounded.
Taliban insurgents often inflate casualties inflicted on Afghan government forces and foreign troops.
Violence across Afghanistan last year reached its worst levels since the Taliban were ousted by U.S.-backed Afghan forces in 2001, with civilian and military casualties hitting record levels.
The violence underscores the challenges ahead as U.S. and NATO forces begin to hand over security responsibility to Afghan troops, allowing foreign troops to withdraw gradually from an increasingly unpopular war.
The process, announced last week, will begin with the handover of seven areas in July and culminate in the withdrawal of all foreign combat troops by 2014.
(Reporting by Elyas Wahdat; Writing by Hamid Shalizi; Editing by Paul Tait and Alan Raybould)