Somali police have arrested an unknown number of people from a mosque in the capital, Mogadishu, while searching for insurgents following a grenade attack.
Mogadishu's Bakara market is the city's lifeline
A BBC correspondent in the city says the mosque raid occurred in a southern suburb during evening prayers.
Mogadishu is suffering from recurring violence, blamed on Islamist insurgents and Hawiye clan fighters.
One person has died in a blast in the city's main market which has re-opened after a five-day weapons dispute.
The BBC's Mohamed Olad Hassan in Mogadishu says the closure affected most of the city, as many of the residents depend on Bakara market, either to earn a living or to buy necessities.
The latest violence comes just days before a planned national reconciliation meeting on 15 July.
Islamists and Mogadishu's dominant Hawiye clan are opposed to the presence of Ethiopian troops in Somalia.
They have been in the country since December, when they helped the government troops to oust the Union of Islamic Courts.
Our correspondent says police were patrolling the Bulo Hubey neighbourhood when the blast occurred, injuring two people.
Police then stormed the nearby mosque during Monday's evening prayers and arrested everyone inside, he says.
After Bakara market re-opened on Tuesday morning, someone threw a grenade into the stalls, killing one person and injuring three.
Our reporter says police fired to disperse the crowd.
Earlier, President Abdullahi Yusuf visited the market to set up a committee to help resolve the stand-off between the government and the traders.
The police, backed by Ethiopian forces, have been searching for weapons in Bakara market, which they say is a hideout for insurgents.
But businessmen at the market accused the government forces of looting.
The government says police operations were aimed at restoring law and order in the city, particularly in the market.
Ahead of this weekend's reconciliation conference, a section of the Hawiye clan, which was previously opposed to the meeting, has agreed to attend the twice-postponed talks, our reporter says.
However, another group of Hawiye clan elders is still opposed to the talks and has called for the immediate withdrawal of Ethiopian troops.
Somalia has not had an affective national government for 16 years, since when rival militias have been battling for control of different areas.