The Taliban have announced the start of a spring offensive across Afghanistan.
In a statement, the group said the fighting would start on Sunday, targeting foreign troops as well as Afghan security forces and officials.
It warned civilians to stay away from public gatherings, military bases, government buildings and convoys.
Meanwhile, initial findings from a Nato inquiry into a deadly attack at Kabul airport on Wednesday suggest the gunman was not connected to the Taliban.
The man, an Afghan pilot, killed eight US troops and a contractor. He was later found dead.
The Taliban said it was behind the attack, but the coalition said there was no evidence for this and the gunman appeared to have acted alone.
Saturday's statement by the Taliban said the group would attack "foreign invading forces, members of their spy networks and other spies, high-ranking officials of the Kabul puppet administration".
It said the war would continue "until the foreign invading forces pull out of Afghanistan".
The Taliban have claimed a series of attacks in recent weeks - including the killing of Kandahar police chief Khan Mohammed Mujahid and a suicide bombing at an Afghan base near Jalalabad that killed five foreign and five Afghan troops.
However on Friday, a Pentagon report said the insurgents' momentum had been "broadly arrested" following a US troop surge last year.
Lutfullah Mishal, a spokesman for the Afghan intelligence service, the National Directorate of Security (NDS), said the Taliban aimed to disrupt Nato's handover to Afghan security forces in some districts.
"They want to show to the Afghans and the international community that Afghan security forces are not capable of taking over," he told the BBC.
"Second, the peace process has had a lot of achievements and that has damaged the reputation and legitimacy of the Taliban."