Migrants have hijacked a merchant vessel that rescued them off Libya's coast, ordering the crew to head towards Malta, reports say.

More than 100 migrants aboard the cargo ship are said to have acted after being told they would be taken back to Libya.

Malta's military said the ship would not be allowed into its waters. Italy's Deputy Prime Minister Matteo Salvini described the hijackers as "pirates".

This comes as the EU says it is ending navy patrols in the Mediterranean.

The EU says the decision to suspend Operation Sophia in September follows a request by Italy.

The mission was put in place four years ago to deter people smugglers and rescue migrants trying to reach Europe by boat. Tens of thousands have been saved.

Lately, the mission has largely targeted smuggling networks as the number of people making the crossing dropped sharply following a controversial deal between the EU and Libya.

But Mr Salvini, the leader of the right-wing League party, has blamed Operation Sophia for continuing to bring rescued migrants to Italian shores.

What about the hijacked ship?

The Elhiblu cargo ship is believed to be carrying more than 100 migrants. Its present location is unclear, as are the circumstances of the rescue off Libya.

The Libyan coastguard has so far made no public comments on the reported hijacking.

A spokesperson for the Maltese armed forces said attempts to contact the ship's captain had been unsuccessful, MaltaToday website reports.

Maltese officials were monitoring the situation and were prepared for any eventuality, the spokesperson added.

Meanwhile, Mr Salvini wrote on his Facebook page (in Italian): "They are not shipwrecked but pirates, they will only see Italy through a telescope."

Mr Salvini has been at the centre of a number of international row over his refusal to allow migrant ships dock in Italian ports.