Insurgents attacked the airport in Mogadishu Tuesday engaging government and Ethiopian troops.

The concerted assaults, an apparent escalation of recent clashes, coincided with the arrival of hundreds of Ugandan troops forming the vanguard of an African Union peacekeeping mission.

Two unmarked Russian-made Antonov cargo aircraft unloaded military vehicles bearing AU markings, including armored personnel carriers. The AU force is coming to relieve Ethiopian troops looking to pull out after defeating the Islamists.

Over a dozen mortar rounds shook the airport, near the camp where 350 Ugandans were staying after landing early on Tuesday.

The artillery barrage was followed by scores of masked fighters firing rocket-propelled grenades and machine-guns at government and Ethiopian troops and at a base nestled in Mogadishu's industrial area.

A local journalist pinned down by gunfire and having found refuge at a nearby hospital reported at least two civilians killed in the crossfire.

The brazen frontal assault underscored the unenviable task facing African Union troops who will try to restore stability and peace to a country stuck in perpetual lawlessness and anarchy since 1991.

A witness who saw the mortar rounds strike the airport could not confirm any casualties.

"The military side of the airport has been hit. We cannot cross from this side to the other side. We don't know if anyone has been wounded there," the witness said.

Most of the Ugandans had been airlifted in by the Algerian air force aboard C-130 cargo planes.

The last foreign peacekeeping mission, a well-funded joint US and UN operation, ended in disaster and withdrawal in 1995 following relentless street battles with local militiamen.

Last week, 35 Ugandan officers landed in Baidoa, the interim government's temporary capital in south-central Somalia. More are set to follow to complete the 1,600 troops forming the Ugandan contingent.

The proposed 8,000-strong AU force will back Somali President Abdullahi Yusuf's government as it seeks to bring the war-torn country under its authority.

Last year's Christmas period saw Yusuf rout rival Islamist factions backed by the power of the Ethiopian army. They fled south, vowing to continue a holy war against foreign troops while adopting guerrilla tactics.

The insurgents are suspected of comprising both Islamist troops and clan militiamen whose private fiefdoms are threatened by strong central rule.

(China Daily via agencies March 7, 2007)