A Greek-owned aframax tanker and a Singaporean VLGC have crashed off of the Lion City.

Pantheon Tankers’ 105,000-dwt Astro Saturn (built 2003) and the 82,400-cbm Crystal Sunrise (built 2013) came into contact in the early hours of Tuesday.

A spokesperson for Kumiai Navigation, owner of the Crystal Sunrise, says nobody was injured during the incident.

While some of the vessel’s butane cargo escaped, there are no reports of any oil pollution as a result of the collision.

The Kumiai spokesperson says the accident occurred at 02:30 local time on 17 April shortly after a pilot had boarded the Crystal Sunrise at Singapore Pilot Western Boarding Ground Alpha.

"The vessel is in stable condition and now safely anchored outside Singapore while the situation continues to be closely monitored," he said.

"The incident has been reported to all relevant authorities and the P&I Club and vessel’s insurers have also been notified."

According to the Singapore Maritime Authority the Crystal Sunrise sustained damage to its ballast tank, while some butane escaped from one of its cargo tanks.

"As liquefied butane has a high evaporation rate, MPA has assessed that any leaked butane would have been carried southward away from mainland Singapore, where most of it would have rapidly dissipated to below flammable levels within an hour and pose no risk to shipping," a statement said.

The Singapore Maritime Authority adds the Astro Saturn's anchor was damaged along with its bow.

The tanker has been inspected by Class, found to be seaworthy and will continue trading until its next scheduled drydock.

The tanker was laden at the time of the incident but has since started discharging its cargo.