Afghan police are investigating whether Canadian peacekeepers in Kabul were the intended target of Thursday's failed suicide bombing.

The explosion happened at an abandoned Queen's Palace, about half a kilometre from a base where 200 Canadian peacekeepers are living.

CTV's Matt McClure, reporting from Afghanistan, told Canada AM that about 8 p.m. local time Thursday, there was a loud explosion that Canadian troops witnessed. "In the aftermath, what police there discovered was a man's body."

However, there are conflicting reports about whether the man was playing with explosives and they went off or if he was planning an attack on the Canadian peacekeepers, which is the theory favoured by Afghan police.

"We think he may have been preparing to carry out some sort of attack," Police Commander Abdul Hadi told The Associated Press.

An Afghan soldier at the palace, Mohammed Mokim, said the dead man -- who had a long beard and was wearing a traditional shalwar khameez -- appeared to be Afghan.

A Department of Defence spokesperson in Ottawa said it was doubtful the Canadians were going to be attacked.

"At this point, we've got no information to indicate that Canadian peacekeepers were the target," Lieut. Diane Grover told The Canadian Press.

Defence Minister John McCallum warned the mission in Afghanistan is a dangerous but important one.

"It speaks to our ... commitment to peacekeeping and it puts us into the war on terrorism, which is very important," McCallum told Canada AM.

"But I've said many, many times that Afghanistan is a very dangerous, volatile place. So it's not at all easy and we have seen a foretaste of that in the last 24 hours."

Despite the incident, McClure said peacekeepers are "very upbeat about their mission."

Close to 15 peacekeepers have died on duty in Afghanistan. On Thursday, a German peacekeeper was killed and another wounded when the vehicle they were driving struck a landmine on a road about 15 kilometres south of the city.

The Canadian peacekeeping mission has just begun in Afghanistan, with an advance party of 155 soldiers in the area waiting for vehicles and equipment.

The Canadians are part of the UN-mandated International Security Assistance Force, made up of some 5,000 troops from 29 countries. Led by Germany and the Netherlands, the force is charged with patrolling Kabul.

They might be in the region, but the National Post, citing anonymous military sources, reported Friday the federal cabinet has actually not yet formally approved the mission.

"We have troops in the ground, in harm's way, and they still haven't signed off on the mission," said one senior officer. "It's incredible."

McCallum denied there was any delay in approving the mission.

"The mission is fully approved. We're moving ahead," he said. "It's a formality to get the official approval, but it's a done deal. It has been for some months."

Canada is contributing 1,800 soldiers to the UN-mandated peacekeeping force in Kabul. A battalion group of about 1,000 troops will be in Afghanistan by August.

With a report from The Canadian Press