At least two dockworkers were killed and four hospitalized with injuries yesterday afternoon, with another five feared missing, following an explosion on a cargo ship moored off the port of Perama, west of Piraeus. The explosion occurred during welding work aboard the Friendship Gas tanker, which was undergoing repairs, according to the Merchant Marine Ministry. The blast provoked a blaze that firefighters were dispatched to extinguish. Rescue workers were searching the vessel to establish whether anyone else had become trapped aboard the ship. Two bodies had been discovered by last night. Neither of the men was identified. The head of the workers’ union, Sotiris Polikoyiannis, said that of the seven men originally missing, five were Greek and two were foreigners. At least two of the four injured were being treated for burns, although it was not immediately known how serious their injuries were. The tanks of the cargo ship had been relatively empty at the time of the blast, according to firemen who said full fuel tanks would have triggered a massive explosion. The tanker was used to carry natural gas and there was also speculation that it had not been cleaned properly before the welding work began. President Karolos Papoulias expressed his «deep sorrow» for the loss of life at the port, while Communist Party leader Aleka Papariga called for those responsible to be brought to trial. Last year, two workers died in a ship explosion and ensuing fire in Perama, triggering a protest by workers.