Two British soldiers and two police were killed in southern Afghanistan where thousands of troops have moved into Taliban strongholds ahead of August polls, officials said Sunday. Afghan, US, British and Danish security forces are pushing into parts of Helmand, an opium-producing province where the militants have established a firm grip, in some of the largest operations since the Taliban's 2001 ouster. The forces have met with little resistance, although some 200 Marines have seen days of heavy fighting, commanders said, adding that many areas have been seeded with mines, a commonly used Taliban guerrilla tactic. "The main aims of the operations are to extend security throughout the areas so as to allow the local population to enjoy a normal life and take part in the forthcoming elections free from intimidation and violence," a British military statement said.