Canadian troops are part of a British-led offensive that launched Tuesday in an effort to drive out Taliban extremists and improve the "quality of life" for people in a volatile region in southern Afghanistan.

A force of more than 200 Canadian soldiers from the Royal Canadian Regiment battle group is part of Operation Achilles, which will eventually involve 4,500 NATO and 1,000 Afghan soldiers.

The International Security Assistance Force (ISAF) says the troops will sweep northern Helmand province, targeting the Taliban as well as foreign terrorists and drug warlords.

"Our first manoeuvre elements reached their positions earlier today," Maj.-Gen. Ton van Loon, commander of regional command south, said.

"It signifies the beginning of a planned offensive to bring security to northern Helmand and set the conditions for meaningful development that will fundamentally improve the quality of life for Afghans in the area."

The International Security Assistance Force (ISAF) is calling Achilles the largest multi-national force ever fielded in a single operation.

As part of the effort, the Canadian soldiers will be tasked with setting up a blocking position in the Maywand district inside the northwestern border of Kandahar province.

"NATO forces are moving in, the Canadians are established where they are now and heavy fighting is already reported up in Helmand province," CTV's Tom Clark reported from Kandahar on Tuesday morning.

Canadian officials said the Gagetown, New Brunswick-based soldiers will attempt to prevent the Taliban from retreating through the district. They will also target bands of local insurgents and the drug lords who deal in opium.

Officials estimate that as much as 40 per cent of Afghanistan's poppy trade comes from Helmand.

Despite a campaign by the Afghan government to eradicate opium production, it rose last year, generating an estimated $3 billion in illegal economic activity.

Speaking at a news conference attended by more than a dozen Afghan journalists, van Loon appealed to people who live in Helmand to shun the Taliban.

"To the people of northern Helmand who are fed up with being trapped by Taliban extremists, foreign terrorists and established drug lords, my message is clear. This operation is for you.''

Van Loon said once the Taliban are eliminated, development agencies will begin refurbishing the 54-year-old Kajaki dam to bring more electricity and water to the region.

The dam controls the headwaters of the Helmand River, which is part of a watershed containing almost 40 per cent of the entire country's water supply.

The plan is to spend more than $25 million to fix the broken turbine and install a new one to help jump start the economy. Officials believe that only about 6 per cent of Afghans have access to electric power.

A force of British Royal Marine Commandos has been keeping guard at the dam from a series of strong points dug into the mountainous terrain.

Meanwhile, the Associated Press reports in Jabar, a rocket attack on a U.S. base was followed by a coalition airstrike that killed nine people including a 6-month-old, officials and relatives said Monday.

The incident is one of the latest in a string of civilian deaths that threaten to undermine the Afghan government.

The airstrike took place late Sunday in Kapisa province north of Kabul, and just hours after U.S. Marines fired on on civilian cars and pedestrians following a suicide bombing in eastern Nangahar province that wounded a U.S. Marine.

Up to 10 Afghans died in the aftermath of the Nangahar suicide attack. And on Tuesday, hundreds of students from Nangahar University protested the killings.

President Hamid Karzai condemned the bombing, "which caused the American forces to fire on civilians," and a statement said relatives of the dead wanted the "perpetrators" brought to justice.

Last fall, Canadian troops led a major offensive, Operation Medusa, to break the back of militant strength in arid farmland west of Kandahar.

Operation Medusa was a very different type of offensive than the latest one, Clark told CTV's Canada AM.

"The big Canadian offensive from last year was almost more like conventional warfare -- it was artillery and it was flattening buildings, and it was armoured vehicles rolling all over the countryside -- this is going to be very different," he said.

"Basically this operation is going to be very directed at the top Taliban leadership, so it's not going to be mass bombing, it is going to be precision bombing."

Brig.-Gen. Tim Grant, the senior Canadian commander said he doesn't expect the same type of bloody pitched battles between Canadians and Taliban that took place last year in the Panjwaii and Zhari districts west of Kandahar city.

"I don't expect to see and I hope not to see any fighting by Canadians in the Maywand district,'' said Grant.

"If things go well then we won't have to fire a shot in anger. If the Taliban choose to stand and take us on, then they will learn how robust the Canadian force actually is.''

With reports from the Canadian Press and the Associated Press