TUNIS (Reuters) - Shelling in Tripoli has stopped 280 migrants, whose boat was intercepted at sea and returned to Libya, from disembarking and they will have to spend the night aboard a coastguard ship, the United Nations migration agency said on Thursday.

“The situation is tragic. Hundreds of people, drained after a perilous 72-hour journey. They will spend the night on an overcrowded boat in tense circumstances,” said Federico Soda, head of the International Organisation for Migration’s Libya mission, in a statement.

It was not immediately which countries the migrants were from but Libya is a major way station for migrants attempting to travel from Africa to Europe.

At least six boats have left Libya this month carrying about 500 people attempting the sea-crossing to Europe, though Italy has declared its ports unsafe due to the coronavirus epidemic.

Officials in Tripoli said the intensity of shelling on Thursday, some of which had previously targeted the port, meant it was not safe for disembarkation, IOM said.

The IOM is providing them with water and food, it said. A curfew in Tripoli to help stop the spread of the coronavirus is also complicating efforts to bring them off the ship, it added.