All cargo on ship that caught fire properly declared: Source

New Delhi, June 10 (CNA) All cargo on the Wan Hai 503 container ship that caught fire off India's west coast on Monday was properly declared, while the cause of the fire remains under investigation, a source involved in the probe told CNA on Tuesday.

Customs documentation had been filed in every country the vessel passed through, the source said, amid speculation that the ship, operated by Taiwan-based Wan Hai Lines, might have been carrying illegal cargo.

As the fire occurred on a joint service route involving multiple shipping companies and containers, the exact origin of the blaze and the container responsible remain unknown, the source added.

Indian media outlet ETV Bharat reported earlier that the ship carried hazardous cargo, including flammable solids and liquids, as well as toxic substances.

"The containers in the ship have dangerous cargo, including Class 3 (flammable liquids), Class 4.1 (flammable solids), Class 4.2 (spontaneously combustible substances) and Class 4.6 (toxic substances)," the report quoted a senior officer at Azhikkal Port as saying.

The Wan Hai 503 departed from Kaohsiung in late May, with port calls in Hong Kong, China, Singapore and Sri Lanka, before heading toward Mumbai.

The fire broke out on Monday while the ship was sailing off the coast of southern India near Beypore Port, after departing Colombo on Saturday evening.

According to the Taipei Economic and Cultural Center in India, 18 of the 22 crew members onboard were rescued after abandoning ship, while four -- including two Taiwanese, one Indonesian and one Myanmar national -- remain missing.

Five of the rescued crew sustained injuries: two Chinese crew members had burns; one Myanmar national suffered facial burns; another from Myanmar sustained general burn injuries; and an Indonesian crew member, though seriously burned, remains conscious.