Several bomb explosions have hit Afghanistan's capital Kabul, killing one person and wounding more than 40 others, most of them security personnel. The attacks come a day after two blasts injured at least seven people in the city.

Afghan officials say that the targets of Wednesday's bomb attacks in Kabul were buses taking government personnel and security forces to work.

Interior Ministry spokesman Yousuf Stanezai gave details of the first bombing, which took place in the center of the capital.

"[A] Ministry of Defense employees' bus was passing through that area," he said. "The explosives were placed in a pushcart. So when the bus was passing through that area the explosives were exploded and a number of civilian and military personnel have been injured in that explosion." 

Stanezai says a second remote-controlled blast hit a bus carrying workers to the Ministry of Commerce. He says that one person died instantly in that attack and several others were injured.

Police also said a third bomb went off in eastern Kabul, targeting an Afghan army convoy, but no casualties were reported.

Spokesman Stanezai says the terrorist attacks are aimed at destabilizing Afghanistan and efforts to reconstruct the country.

"These are their [terrorists] last attempts to create a kind of fear among the Afghan people," added Stanezai. "But on behalf of the security forces and the government I would like to assure the people of Afghanistan that the terrorists will never succeed."

The capital of Afghanistan is considered relatively safe and bomb explosions in Kabul are rare. But on Tuesday, two similar attacks wounded several people in the city, where thousands of NATO-led peace troops are helping Afghan forces to maintain security.

Violence by Taleban insurgents has surged in Afghanistan this year but most of the attacks have taken place in the south and east of the country. The rise in terrorist activities is being described as the worst since the removal of the Taleban from power in 2001.

In recent weeks, the U.S.-led anti-terror military coalition has killed scores of militants in the south and east of the country.