MOGADISHU (Reuters) - A bomb tore through a senior policeman's car in Somalia's capital on Monday, a day after suspected Islamist militants shelled an area where the president was due to speak and attacked a city center cafe, witnesses and officials said.
No one claimed responsibility for the assaults which officials said wounded two mechanics working on the car on Monday and killed 13 people at Mogadishu's Oromo Cafe on Sunday.
It was not immediately clear if the shells caused any casualties on Sunday in the Huriwa district where President Hassan Sheikh Mohamud was due to attend celebrations marking the anniversary of the violence-wracked country getting its flag.
Al Qaeda-linked group al Shabaab has launched a string of bomb and gun attacks in Mogadishu and other centres -- and promised to step up action after African and Somali troops pushed it out of a coastal stronghold a week ago.
The bomb was planted in the car of the police chief of the city's Blacksea area, near the bustling Bakara market on Monday, police major Ahmed Kassim told Reuters.
"The car exploded as two mechanics started the engine to test the car," he added, blaming al Shabaab.
The evening before, attackers detonated a car bomb in front of the popular city center Oromo Cafe, leaving its entrance charred and spattered with blood.
Shortly before that, five shells were fired into the city's Huriwa district, witnesses said, though the government did not comment on those accounts
President Mohamud, who was not injured, addressed the anniversary event in Huriwa later in evening and told the crowd the death toll from the Oromo cafe bombing had risen to 13. Early reports had said seven people died.
"They have killed innocent people who were just resting. It shows the hopelessness of al Shabaab," he said.
Al Shabaab wants to topple the government, which it says is a puppet of Western powers, and aims to drive out African Union peacekeepers, who still provide the backbone of security as the Somali army is slowly rebuilt after years of civil war.
Al Shabaab has been steadily driven out of towns in its heartland of south and central Somalia by an African and Somali military offensive. On Oct. 5, the group lost control of Barawe port, which had offered a conduit for arms imports.
Officials and diplomats say the loss of Barawe and the U.S. military strike that killed al Shabaab's leader last month have dealt a hefty blow, but it was far too soon to declare victory over a group skilled at guerrilla warfare.
Al Shabaab said last week it would prove it was still a potent force.
Reporting by Abdi Sheikh; Writing by Duncan Miriri; Editing by Andrew Heavens