Armed Islamist militiamen are gathered in the shade in a Mogadishu suburb, 18 Apr 2007

Heavy fighting between insurgents and Ethiopian troops continues in Somalia's capital, where residents say at least 30 people have been killed and at least 100 wounded in the past two days.

Reports from Mogadishu Friday say Ethiopian troops have launched artillery rounds from the presidential palace.

Ethiopian troops also have blocked off key roads after one of their bases in southern Mogadishu was attacked by a suspected suicide bomber on Thursday. The number of casualties from the blast is not known.

On Thursday, a United Nations official said Somalia faces a humanitarian catastrophe unless the fighting subsides and the interim government starts cooperating with aid workers. The official, Eric Laroche, accused the government of preventing aid from reaching thousands of displaced people outside Mogadishu.

The world body is urging the interim government to allow aid workers to help at least 100,000 Somalis in the neediest areas. The U.N. says that some 218,000 people have fled Mogadishu since February 1.

The capital has been wracked by violence since late last year, when Ethiopian troops helped Somalia's interim government drive a rival Islamist movement from power. Islamist and clan-based militias have since launched numerous attacks on government-related targets.

Some information for this report was provided by AFP, AP and Reuters.