Dutch troops ended their mission in Afghanistan Sunday after four years, in a departure experts say signals the beginning of a drawdown of foreign forces that will leave a worrying void. The pull-out is the first significant drawdown of troops from the Afghan war, now in its ninth year, and comes as Taliban-led violence worsens and US forces suffered their worst month for casualties. Troops held a “change of command” ceremony at the main military base in central Uruzgan province where most of the country's 1,950 soldiers have been deployed, said a Dutch embassy official. NATO's International Security Assistance Force (ISAF), which had asked the Dutch to extend their mission by a year, paid tribute to the Netherlands' contribution and said it would maintain its current capacity in the area. “Dutch forces have served with distinction in Uruzgan, and we honor their sacrifice and that of their Afghan counterparts during the Netherlands' tenure in the province,” Maj. Joel Harper, an ISAF spokesman, said in a statement. “We have planned for the transfer to the new multi-national operation to ensure a smooth transition... We will maintain current capabilities,” he said. The Netherlands' deployment began in 2006 and has cost the lives of 24 soldiers. NATO's request for an extension of the mission sparked a political row that led to the Dutch government's collapse in February, and they announced drawdown. Switzerland is the only country to have withdrawn its force until now, bringing its two soldiers home from Afghanistan in March 2008, NATO said. A Netherlands Foreign Ministry official said all soldiers would return home by September, while most hardware, including four F-16 fighter jets, three Chinook and five Apache helicopters would be back by the year's end. Canada is set to withdraw its entire force of 2,800 troops in Afghanistan next year, while Britain and the US have signalled that some troops will also leave in 2011 with an overall aim to end combat operations in 2014. Roadside bomb kills six A minibus full of civilians struck a roadside bomb in southern Afghanistan early Sunday, and Afghan officials said six of those on board were killed. Sunday's blast in Kandahar hit a bus in the Maiwand district outside Kandahar city, according to provincial spokesman Zalmai Ayubi. A NATO patrol arrived soon after the explosion and treated the wounded at the scene, the coalition command said. A NATO service member died Sunday after an insurgent attack in south, the coalition said in a statement. It did not provide further details. In the Afghan capital, Kabul, more than 200 demonstrators marched toward the presidential palace to protest the alleged killing of 52 civilians by a NATO rocket strike in the south. They carried photos of children allegedly killed or wounded in the strike and shouted “Death to America! Death to NATO!” “We should not tolerate such attacks. The Americans are invaders who have occupied our country in the name of fighting terrorism,” said 22-year-old Ahmad Jawed, a university student. He said the Afghan government was equally to blame for failing to exert control over NATO troops. “We don't have a strong enough government to protect the rights of the Afghan people,” Jawed said.