Five mortar bombs struck northern Mogadishu on Monday, killing at least three people, wounding several others and flattening homes in the Somali capital's latest outbreak of postwar violence, witnesses said.
Near-daily attacks blamed on ousted Islamist hardliners have put pressure on the interim government, which is struggling to restore stability so Ethiopian troops who helped it take the capital over the New Year can return home.
But with few signs a proposed African Union (AU) peacekeeping force will be on the ground soon, Mogadishu -- already one of the world's most dangerous cities -- seemed to be sliding further into chaos.
Before dawn on Monday, mortar rounds crashed down on residents as they slept in a northern district.
"In one house, a man and his son died while his wife and daughter were injured. They have been rushed to hospital," one local, Mohamed Nur, said by telephone. "Another woman died in our neighbourhood and at least three other people were wounded."
It was not clear who fired the bombs, which a Reuters TV cameraman said obliterated the single-room corrugated iron shack where the father and son were killed.
The government suspects Islamist remnants, who have vowed to wage a holy guerrilla war, along with foreign extremists.
Underlining the security threats in a nation mired in anarchy for more than 15 years, a statement posted on an Islamist Web site on Monday threatened to shoot down all planes using Mogadishu's bullet-scarred international airport.
"We will shoot down any aircraft landing or taking off so as to cripple the economic sources of the enemy," the self-styled Popular Resistance Movement said on the qaadisiya.com site. "We have all the equipment needed for these operations."
The warning followed an audacious attack on Sunday that targeted a heavily guarded public gathering of top security officials in the southern port of Kismayu.
Four people died, and senior military and police commanders were among more than 20 people injured.
Diplomats have urged rich nations to back and fund an AU peacekeeping mission to stabilise Somalia, but only about 4,000 troops have so far been pledged of the 8,000 called for.
Uganda was the first nation to offer soldiers, but its parliament is still studying the plans. On Monday, AU Peace and Security Commissioner Said Djinnit said the regional body was waiting for Kampala to confirm a date for its deployment.
"The AU is looking forward to the approval of the deployment ... by Uganda's parliament before we announce the D-day for deployment of (other) troops," he told reporters.
Speaking after a meeting of AU members in the Ethiopian capital Addis Ababa, he said Nigeria, Burundi, Malawi and Ghana had also offered to send soldiers.
The United States has pledged $40 million, the EU 15 million Euros and Britain $8 million to fund the mission, Djinnit said.
But the mounting violence will make countries more reluctant, experts say, and the clock is ticking for the government and Ethiopia's Prime Minister Meles Zenawi, who said last month he wanted his thousands of troops out "within weeks".