A 10-year-old Stolt chemical tanker has been rocked by an explosion while berthed at the port of Ulsan in South Korea.

The incident aboard the 43,478-dwt Stolt Groenland (built 2009) occurred at around 11:00 local time, a company spokesman confirmed.

The Cayman Islands-flagged tanker also suffered a fire, but the extent of the damage is unknown. It was extinguished on Saturday.

“All crew of the vessel are safe and unharmed and have assembled on shore,” the Stolt Tankers spokesman told TradeWinds.

“Coast Guard and local authorities in Ulsan are responding to the fire. Stolt Groenland is currently in a stable condition alongside.”

Stolt said the safety of those in the vicinity of the vessel was “paramount to the company”. The exact cause of the incident is yet unknown.

The Norwegian tanker owner said it had activated its emergency response team and was “liaising with local authorities”.

The fire had spread to a second vessel moored alongside the Stolt Groenland, Odfjell's 9,118-dwt Bow Dalian (built 2012).

Crews evacuated

Stolt said in an update: "All seafarers aboard Stolt Groenland have been safely evacuated with one minor injury reported to one of our crew who has meanwhile received medical attention.

"The families of the crew have been informed. Emergency responders will continue to maintain a cooling water spray over the ship overnight."

It said the full extent of damage to ship and cargo remains to be established.

Norne Research said it was later confirmed that there were two explosions most likely caused by the overheating of styrene monomer cargo.

There were 10 Russian and 15 Filipino crew on board.

The ship remains stable with no cargo or fuel reported as released into the water, while Bow Dalian has shifted away from Stolt Groenland, Stolt said.

Norne added: "Stolt-Nielsen is reporting its 3Q results this Thursday and we anticipate to hear more about the incident," it said.

"There will be a one-time cost included in our estimates for 4Q19 following the awaited official calculations. However, our long-term view is based on the chemical tanker rate recovery expectations and will not be changed after this."

Odfjell crew okay

Odfjell told TradeWinds that its crew is okay.

"The damage assessment is currently ongoing and will be established during the forthcoming days," it added.

"The crew reacted in a timely manner and released sprinkler and foam according to our procedures before the Bow Dalian was evacuated. This reaction has clearly mitigated the potential consequences for the crew and for the vessel."