KABUL (AFP) - A bomb killed three Nato soldiers in southern Afghanistan, the joint force said Sunday, bringing to eight the number of foreign soldiers killed in the country in the most deadly weekend this year. On Saturday, Natos International Security Assistance Force (Isaf) said five of its troops had been killed in a suicide attack at an Afghan army base in the eastern province of Nangarhar, in which four Afghan soldiers were also killed. On Sunday Isaf said three more of its troops had died on the same day in the south of the country in an improvised bomb explosion, a weapon of choice for the Taliban and other insurgent groups. The force did not provide further details, including the nationalities of those killed in line with policy, but southern and eastern Afghanistan are dominated by US troops. There are about 140,000 foreign, mainly US, troops deployed in Afghanistan to help President Hamid Karzais Western-backed government defeat the Taliban. After a bloody 2010 in which 711 foreign troops were killed, at least 128 have been killed so far this year. The traditional fighting season has begun in the country, with improvements in the weather. The toll is based on a count by www.icasualties.org, an independent website counting military deaths in Iraq and Afghanistan.