Malta refuses to allow a tanker which rescued 102 African migrants permission to dock.
The government was earlier told by the European Commission that it had a duty to admit the passengers on humanitarian grounds.
The commission said the island had a humanitarian duty to take in the migrants, who were saved from a boat off the Libyan coast.
Among those aboard the tanker are an injured woman, four pregnant women and a five-month-old baby.
But Malta says it told the captain of the M/V Salamis the ship did not have permission to enter its territorial waters and insists its decision to deny entry is in keeping with international law.
The BBC reports naval medics visited the tanker on Tuesday to check the state of health of the migrants and distribute food and water, and the government has concluded that no evacuations are necessary.
Just before the latest incident, another 111 migrants arrived from Africa in a rubber dinghy at Delimara, on the south-east coast.
