MANILA — A large search-and-rescue operation was underway off the western Philippines on Thursday after a passenger ferry caught fire, killing at least five people and leaving dozens of others unaccounted for.

The Philippine Coast Guard said 43 people had been rescued from the MV June Aster, while the vessel remained afloat but badly damaged and listing after the fire was extinguished.

The ferry was carrying 117 passengers and 17 crew members, according to the Coast Guard. Based on the latest figures, more than 80 people were still unaccounted for, although authorities cautioned that the numbers could change as the rescue operation continued.

The vessel had departed from Baseco in Manila and was travelling toward Coron in Palawan, a major tourist destination known for its beaches, diving locations and island attractions. The fire broke out on Wednesday evening as the ferry approached its destination.

Rescuers have deployed Coast Guard vessels, high-speed response boats and other government assets. Military personnel, fishermen and private volunteers have also joined the effort to locate missing passengers.

Search operations have been complicated by strong currents and changing weather conditions. The Coast Guard is also using drift-modelling technology to estimate where passengers could have been carried by the sea.

Officials have not yet established what caused the fire. Thick smoke and extreme heat around the damaged ferry have also prevented rescuers from safely entering parts of the vessel, while authorities remain concerned about possible explosions.

The incident has again drawn attention to maritime safety in the Philippines, where ferries remain an important means of transportation between the country’s many islands. Authorities are expected to investigate the circumstances surrounding the fire once the immediate rescue operation is completed.

For now, rescuers are concentrating on finding survivors and accounting for everyone listed on the ferry’s manifest as the operation continues off Palawan.