NATO forces and foreign civilians have been increasingly attacked by rogue Afghan military and police, eroding trust between the allies.
The Taliban attackers and at least five Afghans were killed at the air base in Jalalabad, Afghanistan.
Initial reports said 17 people were beheaded by the Taliban for dancing and singing. Taliban leaders fighting over two women triggered the killings, says a provincial official.
Officials in Afghanistan suspect the Taliban used a magnetic bomb to disrupt NATO supply lines in the north, just weeks after Pakistan reopened eastern and southern lines.
The Taliban claimed the woman committed adultery. A video showed some 150 men perched on a hill to watch the execution praising the attackers.
Taliban militants killed at least 20 people in an all-night battle with Afghan security forces at a popular resort near Kabul.
The Taliban issued a statement ahead of today's NATO summit in Chicago, expressing frustration with the coalition's moves to 'prolong the occupation.'
Gunmen killed a senior member of Afghanistan's High Peace Council Sunday morning, in yet another signal that some elements within the insurgency are against talks.
The Taliban detonated a car bomb around dawn, shortly after Mr. Obama gave a speech invoking 'a new dawn' with the signing of a US-Afghanistan strategic partnership agreement.
Teams of insurgents struck within Kabul and three other cities in coordinated attacks on Sunday. A Taliban spokesman called it the opening of their spring offensive.