A base for South Korean reconstruction aid workers in Afghanistan was attacked with rockets earlier this week, Seoul foreign ministry said Sunday. Two shells of rocket-propelled grenades landed on the ground near the provincial reconstruction team (PRT) camp in Charika, a city in the northern Afghan province of Parwan on Saturday, according to South Korea\'s News Agency (Yonhap). \"No casualties were reported,\" a ministry official said. The ministry will investigate the exact cause of the attack in cooperation with Afghan police, he said. The latest attack is the eleventh against the South Korean base in Charika so far this year. It\'s also the sixth shelling since the death of Osama bin Laden on May 2. Government officials are keeping a close eye on the occurrence of similar attacks on the assumption that the latest shelling could have been done by Taliban forces in retaliation for Osama\'s death. South Korea has stationed some 90 aid workers and police officers in the area as well as about 270 troops to protect them. Charikar has been considered safe due to its proximity to Bagram Airfield, one of the largest military bases of the NATO-led international forces.