More than 500 passengers panicked when they heard an explosion around dawn aboard the KM Kirana IX, docked at the Tanjung Perak port in the provincial capital of Surabaya. "The people heard the sound and started rushing off the boat. At least three people have died, we are expecting more, and others have been taken to hospital," port official Marzuki said. The vessel's owner, Bambang Haryo, told Metro TV that the blast occurred inside a truck onboard the ferry, causing a small fire to break out. The cause of the explosion was unknown. "It was a small fire and it hasn't caused any damage," Haryo said. On Monday, another ferry serving the same route to the city of Banjarmasin in South Kalimantan province on Indonesian Borneo collided with a tugboat and caught fire, killing three and injuring more than 100. The Indonesian archipelago of more than 17,000 islands has a poor sea safety record, and fatal accidents are common. Last week, 13 people were killed when a boat sank off East Java, and 25 were killed when a boat sank off the resort island of Bali.