NAIROBI - The United Nations is investigating the use of its vehicles by suicide bombers who killed 17 African Union peacekeepers at their main base in Somalia, a senior official said Saturday.

The government said Friday Islamist rebels had seized more U.N. vehicles in readiness for further suicide attacks.

There are very large numbers of U.N. vehicles in Somalia that have been used for a variety of projects, Mark Bowden, the U.N. humanitarian coordinator for Somalia told Reuters.

Bowden said the U.N. had been given the chassis number of one of the vehicles used in the attack. We are trying to trace whether it's a U.N. vehicle, he said.

President Sheikh Sharif Ahmed said the suicide attack, which followed the killing of a wanted al Qaeda leader by U.S. special forces, would not deter his government from pursuing stability and called on the world to offer more assistance to his people.

It (the bombing) was shocking... it is irreligious and uncultured, he told a news conference at his hilltop palace on Saturday. The international community has not fully helped Somalia. I urge the world to help the starving Somali people.

Sharif said his government had allowed the U.S. forces to go after the slain al Qaeda suspect.

U.N. PRECAUTIONS

Bowden said the attack on the peacekeepers' base next to Mogadishu airport Thursday would not weaken the U.N.'s resolve to deliver aid to half the Somali population but it could hamper operations on the ground.

We have to take greater precautions around Mogadishu, clearly the airport is more at risk and that will affect our ability to move staff and humanitarian goods, he said.

Insurgents overran U.N. compounds in Jowhar and Baidoa in May and July, seizing aid supplies and vehicles. This has given rise to speculation that the vehicles used in the suicide attacks were captured then.

Bowden said the vehicles could have come from elsewhere. Depending on the marking, they could have been vehicles that have been brought in from the Eritrean peacekeeping operation or they are vehicles that have been used on projects over the years, he said.

The al Shabaab rebel group, which Washington says is al Qaeda's proxy in Somalia, controls much of the south and parts of the capital Mogadishu.

Together with Hizbul Islam, the group has been fighting government troops and African Union peacekeepers to impose its own strict version of sharia law throughout Somalia.

Al Shabaab ordered traders at the country's biggest market, Bakara, to join their fight or vacate their stalls, businessmen said. The group also told them to contribute financially and in kind to their cause.

More than 18,000 Somalis have been killed since the start of 2007 and driven another 1.5 million from their homes.
Bowden said severe drought for the fifth year in a row had compounded the effects of rising violence and pushed half of the population into food aid dependence.

Somalia