Four members of an Afghan family were killed this weekend by a land mine in Helmand province, authorities said. The blast Saturday killed a total of five people and was the latest such explosion in a nation considered by human rights activists to be among the most mine-contaminated countries in the world, the Khaama Press said. Khaama Press cited a recent Landmine and Cluster Munition Report, which estimated about 1 million mines were buried around Afghanistan. Most of the ordnance dates back to the Soviet occupation of the 1980s; however, improvised explosive devices of more-recent vintage caused the majority of the casualties. The most-recent statistics said 812 people were killed by mines in Afghanistan, 88 percent of which were attributed to IEDs. The United States last week awarded a $30 million contract to remove mines and other unexploded ordnance associated with the many US military bases scattered around Afghanistan.