A suicide squad detonated bombs at a newly fortified prison, police headquarters and two other locations in Afghanistan yesterday, killing at least 30 people in the largest city of the southern Taliban heartland.

Kandahar's prison was the main target, but no prisoners escaped, Afghan president Hamid Karzai's half-brother said.

Ahmed Wali Karzai, a member of the Kandahar provincial council, said two of the explosions occurred near his home, which was not damaged.

Mr Wali Karzai said that Canadian troops had reinforced the prison with cement block after a suicide attack in 2008 blew apart the prison gates and freed hundreds of criminals and suspected insurgents.

“They wanted to keep people busy in the city and break the prison, but the Canadians last time did a good job,” Mr Wali Karzai said.