KANDAHAR (AFP) - A key anti-Taliban lawmaker was killed with four other men Thursday when a bomb tore through their vehicle in Afghanistan's flashpoint southern province of Helmand, officials said. There was no immediate claim of responsibility for the attack that killed Helmand MP Dad Mohammad Khan and the others, but the province sees regular attacks by the extremist Taliban, who control several of its districts. "A remote-controlled roadside bomb struck a Corolla-type vehicle in which esteemed MP from Helmand province, Dad Mohammad, the highway police commander and three of Mohammad's bodyguards were martyred," a government spokesman said. The attack was in the Gereshk district on a main highway, interior ministry spokesman Zemarai Bashary told AFP. A cousin of the MP confirmed the killing from the scene. The killing took to 10 the number of MPs who have died in attacks since they were elected in 2005, in Afghanistan's first democratic parliamentary vote, lower house press officer Haseeb Noori told AFP. Meanwhile, an Australian soldier has been killed while trying to defuse an explosive device in Afghanistan, taking the nation's death toll in the war-torn country to 10, the military said Tuesday. The soldier, the second Australian to die in Afghanistan this week, was killed when the improvised explosive device he was working on blew up, Air Chief Marshal Angus Houston told reporters. "The soldier was highly skilled and very courageous," he said. "He was an expert in countering IEDs and he lost his life trying to make the environment safe for his mates and local Afghans by neutralising the threat the device posed."