Kabul, May 14 (IANS): At least five civilians were killed and 46 others, including military personnel, were injured after a massive truck bomb explosion rocked Gardez city, capital of Afghanistan's Paktia province on Thursday, authorities confirmed.

"The explosion occurred in the morning rush hour at 8.30 a.m. The blast sent a thick gray smoke to rise above the site. The number of the people affected in the incident may change," a provincial official told Xinhua anonymously.

"The terrorist tried to attack a provincial directorate of the Ministry of Defence but he was intercepted by soldiers. The attacker then detonated the truck bomb near the facility," he said.

The blast caused massive destruction, destroying several building, including the nearby provincial military court, finance and tax offices, as well as shops and vehicles, according to the source.

Earlier in the day, Tariq Arian, spokesman of the Ministry of Interior, blamed the Haqqani militant group, a military wing of Taliban insurgents, for the attack.

No group has claimed responsibility for the incident.

But the government on Wednesday blamed the Taliban for two separate attacks -- the siege of a Doctors Without Borders (MSF) backed hospital in Kabul and a suicide bombing in eastern Afghanistan.

According to data released on Wednesday by National Directorate of Security, the main intelligence agency of Afghanistan, the Taliban have carried out 3,712 attacks since signing the peace deal with the US, killing 469 civilians and injuring another 948.