Sri Lankan authorities are trying to douse a massive fire aboard a container ship near Colombo’s coast to avoid a chemical as well as an oil spill.

Fire fighters are trying to bring the flames on the ship called X-Press Pearl under control, after it intensified following large explosions earlier on Tuesday, according to Sri Lanka Ports Authority. The fire was first reported by the crew last week. They are safe and have been evacuated.

“We are trying our best to extinguish the fire as it broke out again due to the continuous reaction of the chemical materials in the containers and adverse weather,” Rohitha Abeygunawardena, minister of ports and shipping said in the statement. “We have made plans to carry out future activities in a manner that does not harm the country’s seas and marine environment.”

X-Press Pearl was carrying 1,486 containers containing 25 tons of nitric acid, other chemicals and cosmetics on board, according to a statement released by Sri Lanka Navy. X-Press Feeders, which owns the ship, said specialized fire-fighting equipment has been brought in from Europe to reinforce salvaging operation.

The local authorities have also warned fishermen not to approach the vessel as some containers carrying dangerous chemicals have fallen into the sea after the blasts on Tuesday. State Minister of Fisheries Kanchana Wijesekera urged them to inform authorities if they spot any containers.

Apart from a potential chemical spill there’s a risk of an oil spill of about 100 tons. The area north of where the ship caught fire is well known for dolphin sightings, and any oil spill could threaten marine life in the region.

Sri Lanka is preparing for a tier II oil spill, Marine Environment Protection Authority Chairperson Dharshani Lahandapura said, indicating an accident that needs response teams with specialized knowledge to intervene.

The vessel is carrying about 300 tons of bunker fuel, but some oil has already been removed.

“We are fighting the fire but we are preparing for the worst. Dispersal chemicals and booms available in Sri Lanka had been made ready,” Lahandapura said on phone. “It can escalate into a Tier III spill. But for now the estimate is about 100 tons.”

X-Press Feeders is a common carrier operating a fleet of vessels for transshipment. The vessel was deployed in the company’s Straits Middle East shipping route and caught fire at Colombo anchorage.