It said there had been three collisions resulting in oil spills in recent weeks and it has begun “conducting investigations to determine the causes of the collisions and if there were systemic issues that need to be addressed.”

In the meantime, it is conducting briefings with owners, managers, charterers and agents to reinforce the importance of the safety of navigation in the Singapore Strait

Circulars will be sent out on navigational safety and the port operations control centre will start broadcasts on "the importance of safe navigation and vigilance."

It added: "MPA is gravely concerned about the recent incidents in Singapore's waters. We are working with the Singapore Shipping Association (SSA) to take immediate steps to raise the level of awareness of navigational safety in the shipping community.”

The latest incident on Monday saw the 2,959-teu Hammonia Thracium (built 1997) and the 12,100-dwt chemical tanker Zoey (built 2011) collide, resulting in a spill of fuel.