A bomb exploded outside the offices of a ship repair firm in Keratsini, west of Piraeus, early yesterday, causing widespread damage but no injuries in an attack that police attributed to a settling of accounts. The ammonia dynamite bomb, which had been planted in a dumpster outside the offices of DT Marine, caused serious damage to the ground and first floors of the block and wrecked about 10 parked cars. The force of the explosion shattered windows in nearby apartment blocks. Police ruled out any political motive behind the attack, saying that the owners of the firm claimed to have received threats over outstanding payments. Police forensic experts were examining the remains of the bomb, which had been made of ammonia dynamite placed inside a metal pipe and attached to a slow-burning fuse, in a bid to find clues about the perpetrators.