Sharan (Afghanistan): A suicide bomb attack in the office premises of a construction company in eastern Afghanistan have killed 13 people and wounded 50 more, a spokesman for the provincial governor said on Monday.

The attacker rammed a truck laden with explosives into an office building in the restive province of Paktika, which lies on the border with Pakistan said that all the casualties were workers of the company.

Afghan said that engineers, construction workers and security guards were among those killed in the blast in Paktika's Barmal district, which shares a long, porous border with Pakistani areas troubled by Taliban militancy.

No one has yet claimed responsibility for the attack. The Al-Qaeda-linked Haqqani network, which is based in North Waziristan in Pakistan, is particularly active in Paktika.

The group is loyal to the Taliban and has been blamed for some of the deadliest anti-US attacks in Afghanistan, including a suicide attack at a US base in 2009 that killed seven US CIA operatives.

Islamist insurgents in Afghanistan have been known to target construction workers -- seen by them as in the pay of the Western-backed authorities in Kabul -- as well as military forces and government officials.

Civilians are increasingly getting caught up in the violence that has blighted Afghanistan since a US-led invasion in 2001 ousted the Taliban, triggering an insurgency whose intensity has increased in recent years.

Karzai said the Afghan people wanted to take charge of their own security, but he admitted that would not be an easy task for a country ground down by decades of war and still battling a brutal Taliban insurgency.