The blaze on an X-Press Feeders boxship off Sri Lanka appears to be out of control again after an explosion rocked the vessel.

The Sri Lanka Navy said last Tuesday's blast was reported from inside the 2,743-teu X-Press Pearl (built 2021), which is carrying 25 tonnes of nitric acid.

Eight containers have fallen into the sea and new photos from the Sri Lanka Air Force show flames erupting from the vessel and black smoke billowing upwards in a tall plume.