Lebanon's prime minister has asked the UN Security Council to authorize UN investigators to help probe last week's killing of an anti-Syrian lawmaker in a massive car bombing in Beirut. Prime Minister Fuad Saniora asked the UN commission investigating the assassination of former prime minister Rafik Hariri and 22 others in February 2005 to provide technical assistance to the Lebanese investigation into Wednesday's killing of lawmaker Walid Eido, his son, two bodyguards and six bystanders. Secretary-General Ban Ki-moon sent the letter from Saniora to the council on Thursday, according to copies circulated on Friday. Eido was the latest victim in a string of bombings to have shaken Lebanon since fighting erupted in the Nahr el-Bared Palestinian refugee camp on May 20. His assassination was a further blow to the stability of the small Mediterranean nation, which has been mired in a political power struggle between the Western-backed government and the Hezbollah-led opposition, supported by Syria.