KABUL -- The last British Royal Marines left Afghanistan on Friday, after six months tracking the remnants of Osama bin Laden's Al-Qaeda network without once engaging the enemy.

Around 130 soldiers from 45 Commando boarded a chartered Portuguese commercial jet at Kabul airport to fly to Prestwick in Scotland for debriefing and then home leave, the last of a force that numbered over 1,700 at its peak.

"There are some remaining, but principally logistics and support staff," said Commander Simon Ryan, a spokesman for the forces. "Operations for the time being are over".

The marines arrived in Afghanistan in February on Operation Jacana, a mission aimed at putting highly-trained rapid-reaction forces into areas where Al-Qaeda fighters and the remnants of Afghanistan's deposed Taleban regime had been spotted.

But the marines never found their target -- if it existed at all, Reuters reported.

"We came here ready for combat operations, but we've not actually seen any of that," said 2nd Lieutenant Dan Venables, of Yankee Company, as he prepared to board the plane.

"In terms of what we have been doing, we have achieved more in humanitarian aspects," he said.

The British forces were part of the U.S.-led coalition formed after the September 11 attacks on New York and Washington to track down the perpetrators and their protectors.

But after the U.S. air bombardment that helped the Afghan Northern Alliance sweep the Taleban from power, the enemy managed to slip across the border to Pakistan or melt back into the general population.

When the marines arrived they were left chasing shadows in the Afghan countryside, blowing up weapons caches that dated back to the 1980s when the Mujahideen were fighting Soviet forces.

One commander was embroiled in controversy in Britain after he was accused of exaggerating the mission's successes and the dangers they faced.

Nevertheless, diplomats and analysts said the marines and forces from other countries had contributed significantly to security in the country, particularly in the capital.

"The British have made a contribution, no matter how many Taleban or Al-Qaeda they killed or didn't kill," said one Western diplomat. "Lets face it, the more well-trained troops there are out here from countries which don't have an axe to grind, the better it is for Afghanistan -- in the short term at least."

The United States still has a substantial force in Afghanistan, but its presence is being questioned, particularly in the wake of the latest bombing mistake in which Afghans say over 40 innocent people were killed.

Afghans say American forces mistook traditional celebratory rifle fire at a wedding for an attack, and bombed the party.

British forces initially led the United Nations-mandated International Security and Assistance Force (ISAF) that polices the capital, a role that passed last month to Turkey.

Security is the biggest problem facing the fledgling government of Hamid Karzai as he attempts to rebuild a country shattered by 23 years of occupation or conflict.

Although he has won over many regional warlords and powerbrokers by bringing them into his cabinet, security in the rural areas remains fragile.