KANDAHAR, Afghanistan - A Taliban bicycle bomber killed four Canadian soldiers and injured many more as they were mingling with Afghan children yesterday, switching back to guerrilla tactics a day after NATO commanders had declared a two-week offensive against fighters in this region a "significant success." The four slain soldiers have been identified as Cpl. Shane Keating., Cpl Keith Morley and Pte. David Byers, 22, all members of the 2nd Battalion, Princess Patricia's Canadian Light Infantry from Shilo, Man. The fourth soldier was identified as Cpl. Glen Arnold, a member of the 2 Field Ambulance, from Petawawa, Ont. The blast happened about 9:30 a.m. yesterday, as a group of Canadian soldiers was patrolling the community of Kafir Band in the Panjwaii combat zone just west of Kandahar city, where they had handed out candies to children earlier in the day.

Witnesses say dozens of wary area residents were cautiously approaching the Canadian troops, hoping for promised handouts, when the bomber struck. "I was going to the same place to see if they were giving aid but at once the explosion occurred," said Haji Mohammed, a 35-year-old farmer. "Thank God I didn't get too close. "Everybody was running to their houses. We were hiding because we thought if we went over there we would be shot by someone." The number of troops and Afghans injured is still being determined, but the tally is expected to surpass 40, with NATO confirming 27 civilians wounded, many of them children.

Plans are being made to fly 10 Canadian soldiers who were injured to Landsthul, Germany, for further medical treatment. Pending medical assessments, several other soldiers may also be sent to Germany. None of the troops suffered life-threatening injuries, officials said. The Taliban have claimed responsibility for the attack, which also killed the bomber. In Ottawa, Prime Minister Stephen Harper said yesterday the attack illustrates the "evil" Canadian soldiers are fighting and the nobility of their cause.

"Nothing more than this incident illustrates the evil that they are fighting and the goodwill and the nobleness of the cause that they are taking to the Afghan people," Mr. Harper told the Commons. The fatal bombing was one of three that claimed the lives of at least 19 people across the country yesterday. Outside a mosque in the western city of Herat, a suicide bomber on a motorcycle killed 11 people and wounded 18 others. In Kabul, a car laden with explosives killed four police officers, while 10 bystanders were injured. The violence this year in Afghanistan marks a downward spiral not seen since the Sept. 11 attacks prompted a U.S.-led invasion in 2001 to try to capture al-Qaeda leader Osama bin Laden and overthrow the Taliban government.

The Taliban have regained strength since, but their attacks will not drive Canadian soldiers from Afghanistan, said Canadian Brig.-Gen. David Fraser, commander of NATO forces in the southern region. "We're not going to get deterred from this," he said yesterday afternoon at Kandahar Air Field. "The Taliban continue to attack this country. They continue to attack the people. They attacked children today. That's about as cowardly as you can get."

Yesterday's death toll brings the total number of Canadian soldiers killed in Afghanistan since 2002 to 36. A Canadian diplomat has also been killed. The number of injured has not been disclosed. Nine soldiers have been killed since Operation Medusa, an offensive against the Taliban in Kandahar province, began Sept. 2.

The Canadian deaths are part of bloody year for NATO and U.S. forces. Roughly 130, mostly Canadian, American and British, have been killed. NATO commanders say they need 2,500 more soldiers, plus greater air support, to crush the Taliban threat more quickly. The day before the latest blasts, Brig.-Gen. Fraser and Kandahar's governor, Assadullah Khalid, had been talking about the success of Operation Medusa. The Taliban in the area had been crushed, but the threat of more attacks had not been eliminated, they conceded.

Since the bulk of the fighting ended last Wednesday, Canadian troops have encountered two suicide bombings and a blast from an improvised explosive device (IED). The presence of suicide bombers and IEDs in an area where, according to NATO, 512 insurgents died and 136 were taken prisoner during two weeks of fighting, doesn't surprise Brig.-Gen. Fraser. "There was no lapse in security," he said. "We knew that the Taliban would revert to other attacks, including attacks like this. "This, unfortunately, is the environment that we have to work in here, and we're trying to bring this back to normal and the Taliban just keep wanting to try and destroy it." Yesterday's foray into the village was part of a bid to restore relations with people in the area. Since Thursday, Canadian troops have been visiting with villagers and smiling and waving at people passing by in vehicles, on foot and on bicycles.

Their efforts are part of NATO's plan for severing the Taliban's hold on Kandahar province: Bomb and kill the fighters first, then rebuild schools, water wells and trust amongst locals so that the Taliban won't gain strength again. Not all of the soldiers are comfortable with this role. Sgt. Mike Martin said it's difficult for soldiers to make the transition from killing to mingling with residents. That job, he said, was better suited to soldiers and government workers with Canada's Provincial Reconstruction Team. The suicide bombing weighed on the minds of troops from Petawawa, as they gathered for a barbecue and rare beers in a rock-covered parking lot at the base. For a moment yesterday, it appeared as if the dinner to mark the end of Operation Medusa's battle phase would be cancelled. The troops had encountered their own suicide bomber Sunday on the drive back to Kandahar from a base in the Zhari district. The white van smashed into a light-armoured vehicle, killing one civilian and the bomber and slightly injuring three soldiers. Waving at the children as they continued to Kandahar wasn't easy after that, Capt. Mike Fenton said. "Every time you go outside the wire, everyone knows in the back of your mind it could be you, " he said. "You feel bad for the guys who are just out there because we were just there."