Israel officially admitted that it had sank a Lebanese refugee ship off the coast of Tripoli in northern Lebanon in the summer of 1982, killing 25 out of 56 people on board.

The Israeli Channel 10 reported on Thursday that an Israeli submarine fired missiles at a refugee ship off the coast of Tripoli in northern Lebanon, as part of a secret operation called by the Israeli army "Operation Dreyfus".

The Israeli channel said that a commercial ship carrying 56 Lebanese refugees to Cyprus sailed from the shores of Tripoli during the cease-fire following the Israeli invasion of Beirut, and the exit of Palestinian fighters to Tunisia under international protection.

An Israeli Navy Gal-type submarine followed the Lebanese ship about an hour after leaving Tripoli, and torpedoed the boat killing all 25 Lebanese on board.

The Israeli submarine captain claimed he thought the boat was carrying PLO fighters.

Israeli army claimed the aim of "Operation Dreyfus" was to patrol off the coast of Tripoli to prevent Syrian naval vessels from attacking Israeli navy.

In an internal investigation that lasted about three years, the Israeli army refrained from criminalizing the operation which killed 25 civilians. It said the captain had been acting “within operational orders” describing it as a judgment “mistake."