KABUL, Afghanistan - Taliban militants killed more than 50 people at an airport in Afghanistan's southern city of Kandahar late Tuesday and Wednesday during an audacious 20-hour assault, just as diplomatic efforts to revive peace talks between the Islamist insurgency and the Afghan government picked up momentum.

The attack began late Tuesday afternoon when a group of Taliban suicide bombers armed with rocket-propelled grenades, small arms and hand grenades broke through a main entrance of the airport, said Gen. Abdul Razaq Sherzai, the Afghan air force commander in Kandahar province.

For hours, Afghan forces at the combined military and civilian airport battled Taliban fighters who had taken family members of Afghan troops hostage in a residential area. The sprawling airport is also used by U.S. troops and is a hub of CIA operations, but there is no indication that any Americans were killed or injured in the fighting.

Late Wednesday, Afghan officials said at least 50 people, including women and children, had been killed along with all 14 attackers.

The attack is seen as a show of the Taliban's mobility and flexibility as key regional leaders attend a conference in Islamabad, Pakistan, called the Heart of Asia. Afghan, U.S., Pakistani and Chinese officials agreed during the meeting that they will immediately try to jump-start peace talks to end the 14-year Taliban insurgency.

A similar effort by the four countries collapsed this summer after it was revealed that the Taliban's supreme leader, Mullah Omar, had been dead for years. But officials expressed optimism on Wednesday that the talks can eventually be revived.

"There is an affirmation of the need now to engage in this process or maybe, more accurately, reengage in it," said U.S. Deputy Secretary of State Antony J. Blinken, who attended the conference in Islamabad.