The Canadian flights are at the mercy of a dangerous and tenuous situation on the ground, but the airlift will continue as long as the security situation holds, officials said.

More than 1,000 people had been invited, one witness said, as fears grew that it could be the deadliest attack in Kabul this year.

The parents of a Canadian man held hostage in Afghanistan say a recently released video of their son and his family marks the first time they've seen their two grandchildren, who were born in captivity.