People are fleeing areas in the Somalia capital, Mogadishu, that came under attack overnight fearing more violence.
No-one has claimed responsibility for a series of mortar attacks
A BBC correspondent says the port, presidential villa and a minister's house came under fire and two civilians were wounded in a gun battle.
The government says it suspects the attacks were carried out by remnants of the defeated Islamist militia.
In Uganda, MPs have approved sending 1,500 troops to Somalia as part of an African Union peacekeeping force.
A decision on when the AU force will start deploying is expected within 48 hours.
The AU's peace and security council in the Ethiopian capital, Addis Ababa, has set up two working groups to oversee military and financial planning for such an operation.
Ugandan and Nigerian soldiers are expected to be the first to be sent to the Somali capital, where sporadic violence has continued since Ethiopian troops drove out the Islamist administration at the end of last year.
In New York, the United Nations Security Council is considering a resolution which calls on AU troops to take all necessary measures to provide support and training for the Somali security forces.
Dozens of people have been killed in a series of attacks in Mogadishu since the Union of Islamic Courts (UIC) was ousted from the city they had controlled for six months.
No group has claimed responsibility but the government blames the remnants of the UIC forces, saying some 3,500 Islamist fighters are hiding in Mogadishu.
Somalia has not had an effective national government for 16 years.
The BBC's Mohamed Olad Hassan in Mogadishu says most of the people are fleeing from the areas close to the airport, seaport, the presidential palace and any military and police bases in the city.
There are fears of anarchy in Somalia without peacekeepers
"For the last two weeks a day has hardly passed without shelling and heavy gunfire pounding our residential areas, so I do not want to wait for death in my dangerous house," said Halima Hashi Dahir who is preparing to leave his home close to an Ethiopian military camp.
A bus driver who travels out of Mogadishu daily confirmed that many residents have been fleeing.
"People mainly women and children have been leaving the city for nearby regions for the last three days," Abdi Shakur Abdi-karin told the BBC.
Meanwhile, four British citizens, arrested during a Kenyan operation to capture fleeing Somali Islamic fighters, are being deported from Somalia back to the London.
The four men were arrested last month by Kenyan anti-terrorist police and then forcibly returned to Somalia.
They were detained by the British police on arrival under the Terrorism Act.
The Somali government believes the men have links to al-Qaeda, but their families have protested their innocence.