SIDON, Lebanon (AFP) - A top Palestinian official and three other people were killed in a roadside bombing outside a restive refugee camp in southern Lebanon on Monday. Senior Palestine Liberation Organisation official Kamal Medhat, two of his bodyguards and another Palestinian official were travelling in a convoy when the bomb exploded at the entrance to the Mieh Mieh camp near the coastal town of Sidon, an army spokesman told AFP. "The bomb was apparently hidden in a little shed on the side of the road and was detonated as Medhat's convoy drove by," he said. Medhat, who was a close aide to the late Palestinian leader Yasser Arafat, is the highest-ranking Palestinian official killed in Lebanon since the PLO was forced to pull out of the country in 1982 after the Israeli invasion. Medhat, 51, was the PLO's deputy representative in Lebanon and also a former intelligence chief for the mainstream Fatah movement in the country. Abbas Zaki, the Palestinian Authority's representative in Lebanon, blamed Israel for the killing and warned it would have serious repercussions in Lebanon and the Palestinian camps. "Those behind the killing are working in one way or another for Israel," said Zaki, who had left the camp in another vehicle just minutes before the attack. "We are trying to calm the situation inside the camps." Palestinian President Mahmud Abbas, who is also the head of the PLO, "condemned this terrorist crime," according to a statement from his office. Munir Maqdah, who is in charge of security at Lebanon's refugee camps, said the bomb, made up of more than 20 kilograms of TNT, was detonated by remote control. The other victims were identified as Akram Daher, who was in charge of the PLO's youth organisation in Lebanon, and bodyguards Khaled Daher and M Shehadeh. Maqdah said two people travelling in a second car were seriously wounded. The force of the blast tore through the Mercedes in which Medhat was travelling and threw it into a nearby field, witnesses said. Hundreds of camp residents rushed to the site, which was cordoned off by the army. Shots rang out inside the camp after the blast. Tensions have been running high in Mieh Mieh where two people were killed at the weekend in an apparent settling of accounts. between two rival clans. Medhat had visited the camp in a bid to calm the situation. "He was on his way out of the camp where he had visited officials in a bid to ease the tension," Hisham el-Debsi, a PLO official, told AFP. Mehat, also known as Kamal Naji, was a close aide to Arafat when the PLO chief was leading his guerrilla war against Israel from Lebanon. The representative of the Palestinian Hamas in Lebanon, Osama Hamdan, condemned the killing, saying it was aimed at sowing discord in the Palestinian camps, considered breeding grounds for extremist groups. The Lebanese army does not enter the camps, leaving responsibility for security to Palestinian factions.