About 500 refugees and migrants are onboard a boat in distress in the Mediterranean Sea after departing Libya for Europe, humanitarian organisations say.

Italian NGO Emergency said on Wednesday that the vessel – which has 45 women and 56 children on it, including a baby born overnight at sea – was taking on water.

It said its rescue vessel Life Support was heading towards the boat but needed another 10 hours to reach the location in Maltese waters.

The nationalities of those onboard remain unknown.

“It’s a race against time in an attempt to save as many lives as possible,” Albert Mayordomo, head of mission on the Life Support, said in a statement sent to Al Jazeera. “The absence of coordination on the part of the authorities is a grave violation of the law of the sea.”