An explosion in a tightly-packed Afghan marketplace killed at least seven people Saturday. Canadian doctors treated dozens of wounded at Kandahar Airfield.

Officials in Afghanistan said two police officers and five civilians died, while 12 people -- including an eight-year-old child -- were left in critical condition.

The attack was carried out by a suicide bomber, who drove his motorbike into a marketplace in Spin Boldak, near the border with Pakistan, before detonating his explosive.

Survivors were transported to the Canadian base by helicopter, reported CTV's Paul Workman from Kandahar.

He noted there was a side benefit to having Canadian soldiers and doctors assist: "Often Canada's reputation is not the best here, and they hope this will show to the Afghan community how much they are here to help."

The bombing occurred on the first day of Eid al-Fitr, the Muslim holiday that marks the end of the holy month of Ramadan.

"The marketplace where the bombing took place would have been very crowded -- families out visiting each other, offering gifts," Workman said.

"There had been concerns the Taliban would try and do this kind of thing, and of course we've seen this tonight in Spin Boldak."

Afghan police are a major target for the Taliban.

"The Afghan National Police have been targeted a lot over the past year or so. It's a way of terrorizing the community. It's a way of showing the police that the Taliban are very strong and the police are weak," Workman said.

With files from The Canadian Press