Jakarta, Aug. 3 -- The Indonesian government has launched an official investigation into a deadly ferry fire in the Java Sea that killed five people.

The blaze broke out early Sunday morning aboard the KM Mutiara Sentosa II in waters north of Madura Island, off the coast of East Java.

"The government will immediately launch an investigation because we need to know the exact cause of the incident," said Agus Harimurti Yudhoyono, Coordinating Minister for Infrastructure and Regional Development, expressing his condolences to the families of the victims.

Indonesia's National Transportation Safety Committee (KNKT) will lead the probe, which will examine the ship's technical condition, crew readiness, passenger manifests, and weather condit...