KANDAHAR, Afghanistan - Suicide attackers killed at least 19 people, 12 of them young children, when they targeted government buildings in southern Afghanistan on Thursday, the latest blow to a fragile region that has been destabilised by a string of assassinations.

The assault in Uruzgan province also wounded 35 civilians, provincial officials said, and was the deadliest in the south in nearly six months.  

It began with two remote-controlled car bombs, one in front of the provincial governor's compound and the other near the offices for regional state television channel, Uruzgan TV, said the governor's spokesman, Ahmad Milad Modaser.

Up to six suicide bombers then stormed the governor's compound and the police chief's compound in Tirin Kot, capital of Uruzgan, said Interior Ministry spokesman Sediq Sediqqi.

Three bombers detonated their explosives shortly after the attacks began while the remaining attackers were locked in a hours-long gunfight with police inside the compounds, he added.

The Taliban claimed responsibility for the attack and spokesman Qari Yousuf Ahmadi said six militants were involved.

Uruzgan is a largely rural and mountainous province north of Kandahar, to which it has many cultural and tribal links, and the Taliban have long had a presence there.    

The complex assault comes the day after the killing of the mayor of Kandahar, and the same month as the assassinations of President Hamid Karzai's younger half-brother, widely considered the most powerful man in the south, the most senior cleric in Kandahar province, and a former governor of Uruzgan.

Most of the dead were civilians, among them 12 children between the ages of 5 and 13 and two women, Modaser said. Three adult male civilians and two policemen were also killed.

The high toll of young children may have been from families trying to get national identity numbers for their children, which are required to enroll in government schools and only available at the provincial governor's office.  

The governor was in the compound during the attacks but was unhurt, Modaser said, adding the gun battles, which had lasted for some six hours, were now over.

A reporter who worked for Pajhwok, an Afghan news agency, and for the BBC was also killed in the attacks.  

"Unfortunately one hour ago we got the news that our reporter in Uruzgan, Omid Khpalwak, 25, was killed. He was in Uruzgan TV station to arrange an interview," said Danish Karokhil, chief editor for Pajhwok News Agency.

"He was trapped there for three hours and couldn't escape from the battle."