A merchant ship has supplied fuel and water to a boat with around 400 migrants on board - taking off from off the Libyan coast - which is in distress between Greece and Malta but Maltese authorities have ordered it not to conduct a rescue, German NGO Sea-Watch International said on Monday, according to Reuters. 

The vessel, which departed from Tobruk in Libya, was reported to be adrift and taking on water by support service Alarm Phone early on Sunday. Alarm Phone said the boat was in the Maltese Search and Rescue area (SAR).

Sea-Watch International, which located the boat with one of its two planes, on Monday accused Malta of not wanting to rescue the people on board despite them being in serious danger and the vessel struggling with 1.5 meter waves.

"If the boat keeps moving, it might reach Italy and Malta does not have to accept the people," it said on its Twitter account.