The head of Kandahar's provincial council Ahmad Wali Karzai said that the main objective of the attacks were a prison break in the Kandahar city, adding that the attacks on other three other places were an apparent attempt to divert attention.
However, the prison walls could not be breached in the attack as police were prepared for such attacks and the prison was well-protected, he said.
"There had been some information, rumors [were] going on that they were going to hit the prison and the police headquarters," he said.
Karzai said that a hotel, a mosque were a city centre road junction were also attacked by the suicide bombers.
"Houses have collapsed and some shops [collapsed] and people are under the rubble and the government is trying to rescue them. And there was a wedding close to the police station and lots of casualties in there, women and children, because of the glass and all this explosion," he said.
Authorities said that the situation is now under control.
Similar attack were carried by the militants in mid- 2008 on the prison in Kandahar, in which a fuel tanker loaded with explosives was used.
Nearly 1,200 prisoners, including up to 400 suspected Taliban militants, escaped in the attacks, officials said.