LONDON, August 27, 2009 (AFP) - Amnesty International said Thursday civilians were at a greater danger in Afghanistan than at any time since the Taliban extremists were ousted from power in 2001.

The London-based human rights group cited Tuesday's bombing in Kandahar which killed 43 people and Thursday's clinic siege in the Sar Hawza district of Paktika province, which borders Pakistan and is a hotbed of Taliban violence.

The Taliban-led insurgency hit record intensity in the build-up to and aftermath of the August presidential elections.

"With the outcome of voting in Afghanistan unclear, the danger and insecurity facing millions of Afghans continues and in fact is higher now than ever," said Sam Zarifi, Amnesty's Asia-Pacific director.

"Anti-government groups, including the Taliban, have demonstrated a systematic contempt for the safety of civilians by targeting Afghans who want to establish their future through ballots, not bullets.

"The Afghan government and its international supporters have done much to try to protect Afghans from this threat during the election period but they must also show that they will follow the rule of law themselves and will quickly investigate, and if necessary punish, any violation of the laws of war or human rights violations."

In the clinic siege, a fierce gunfight backed by US helicopter fire paralysed the small district after Taliban rebels forced their way into a clinic seeking treatment for their leader, officials and NATO said.

One US soldier and 12 Taliban were killed.

Amnesty called on NATO to launch an immediate investigation into the incident to establish whether international humanitarian laws were broken.

"If the Taliban used the clinic as a shelter to fire from, they've committed a serious violation," said Zarifi.

"But if they were using the clinic for health care, NATO forces had no business firing on the clinic, even if they had cleared out civilians from the facility.

"The bottom line in this incident is that another clinic in Afghanistan is now not working -- a tragedy for a country that already suffers from horrifically low rates of access to health care.

"Whether the Taliban or NATO or both have violated the laws of war, it is Afghan civilians who pay the price."