Militants armed with guns and rocket propelled grenades on Saturday attacked the office of the governor of Afghanistan's Kandahar province, with casualties reported, an official said.
"Small arms fire is still going on. Two RPGs (rocket-propelled grenades) have been fired onto the building so far. The northern and eastern sides of the compound are under direct attack," provincial spokesman Zalmay Ayubi told AFP.
He added, "We have reports of people injured, but no word on fatal casualties so far."
An AFP reporter at the scene said the assault against the heavily guarded compound was launched from a nearby building, where the attackers had ordered shopkeepers to leave shortly before the violence began. Kandahar is the birthplace of the Taliban, and the city and the surrounding province are frequently hit by serious violence.
The Taliban warned in a message released on Friday that this week's killing of al Qaeda leader Osama bin Laden by US forces in Pakistan, would give "a new impetus" to their fight against foreign and Afghan forces.
There are around 130,000 international troops in Afghanistan, two-thirds of them from the United States, battling the Taliban and other insurgents.
Limited withdrawals from seven relatively peaceful areas, only one of which is in southern Afghanistan, are due to start in July ahead of the planned end of foreign combat operations in 2014.
Foreign forces claim that Kandahar and the surrounding area are now safer following months of intense fighting to clear traditional Taliban strongholds.
But nearly 500 Taliban prisoners escaped from Kandahar's prison last month through a huge tunnel in a major embarrassment for the authorities. Also in April, Kandahar's police chief was killed by an attacker in a police uniform.