* Roadside blast kills five policemen
* Rebels, govt troops fight, at least seven die
By Abdi Guled and Ibrahim Mohamed
MOGADISHU, JUNE 9 (Reuters)- Fighting between government forces and rebels, and a roadside blast on Wednesday killed at least 12 people in the Somali capital and wounded 22 others, a medic and residents said.
The anarchic country's U.N.-backed Transitional Federal Government controls just a few blocks of the war-scarred coastal city and its security forces have been fighting to regain Mogadishu's north.
Residents in the first incident said rebels attacked government forces between the president's palace and the main Bakara Market, prompting an exchange of shells and machinegun fire.
"We have so far collected seven dead people and 22 others injured from around Bakara market," Ali Muse, the coordinator of ambulance services, told Reuters.
"Among the dead is a mother. Most of the shells landed in and around the market. Death toll may rise because shelling is still going on."
Somalia has had no effective central government for 19 years and Western efforts to install one to guide the country back to stability have been greatly undermined by an insurgency by al Qaeda-linked al Shabaab insurgents and another smaller group, Hizbul Islam.
In another incident, residents said at least five policemen on patrol died and another was wounded in a roadside blast targeting them.
"I could see five dead policemen and another seriously injured. The area was soon sealed off by the government forces. I was passing near the scene when the explosion happened," Hussein Osman, one resident, said.
Government officials and rebels could not immediately be reached for comment.
Al Qaeda-linked al Shabaab fighters are trying to hold on to the city's north which puts the presidential palace, known as Villa Somalia, within easy range of their crude mortar rockets.
Al Shabaab, and a second hardline group Hizbul Islam, have been fighting President Sheikh Sharif Ahmed's Western-backed government since the start of 2007.
In the last two days, four ministers have resigned. Three stepped down on Tuesday, including a defence minister who said he was quitting because the government had failed to fulfill its pledge to restore order. (Writing by Abdi Sheikh, editing by George Obulutsa and Ralph Boulton)