Afghan authorities say militants launched an hours-long assault on government buildings in the volatile southern province of Uruzgan Thursday, killing at least 19 people and wounding 37 others.

Officials say the attackers armed with explosives and guns targeted the governor's house and police headquarters in Tarin Kot, as well as the base of a militia commander who provides security to NATO convoys. A NATO spokesman said the international coalition had sent reinforcements, including air support, to help the Afghan forces repel the assault.

Medical officials say the casualties include civilians, among them children. The British Broadcasting Corporation also said one of its part-time reporters, a 25-year-old local man, died in the attack.

The Taliban claimed responsibility for the coordinated assault, saying a total of six suicide bombers participated. The group's spokesman also blamed the BBC reporter's death on government forces. The claim has not been independently verified.

In recent weeks, the Taliban has launched a series of high-profile attacks and assassinations of key allies of President Hamid Karzai, even as the coalition transfers more security control to Kabul.

On Wednesday, a suicide bomber killed the mayor of Afghanistan's southern city of Kandahar. Witnesses say Mayor Ghulam Haider Hamidi was meeting with constituents about a land dispute at the time of the attack.

The mayor's death follows last week's targeted killing in Kabul of a senior advisor to President Karzai. And earlier this month in Kandahar, a trusted bodyguard shot and killed President Karzai's half-brother, Ahmad Wali Karzai.

About 33,000 American troops are set to leave Afghanistan by September of 2012. Last week, NATO transferred the first seven areas of Afghanistan to the control of Afghan forces. Foreign combat troops are set to leave Afghanistan by the end of 2014.