Migrants have hijacked a merchant vessel that rescued them off Libya's coast, ordering the crew to head towards Malta, according to reports.
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".
"They are not shipwrecked but pirates, they will only see Italy through a telescope," BBC cited Salvini as saying.
The EU says the decision to suspend Operation Sophia in September follows a request by Italy.
A spokesperson for the Maltese armed forces said attempts to contact the ship's captain had been unsuccessful, adding that Maltese officials were monitoring the situation and were prepared for any eventuality.
