Two passenger trains collided on the Indonesian island of Java early Saturday morning, leaving at least 16 people dead and 31 wounded, police said. The trains, identified as the Sembrani, a first-class "executive" train and the Kertajaya, geared to economy travellers, collided in central Java province en route to the main city of Surabaya at 2:15 a.m. "We have difficulties evacuating victims, and so far we can only identify 12 bodies. Four others are in a very bad shape," First Brigadier Suyono, a local police spokesman who like most Indonesians goes by one name, told Deutsche Presse-Agentur dpa. "About 15 victims are still in critical condition, and we expect more victims and bodies from the train's ruins," he said. The trains were travelling from the capital Jakarta when they collided in the district of Purwodadi. The Kertajaya was stopped when the other train, the Sembrani, hit it from behind, police said. Indonesian Transportation Minister Hatta Radjasa told the media that "human error" might be the cause of the accident. The Kertajaya train engineer was supposed to stop to allow the faster Sembrani to pass in accordance with the transportation law. The engineer died in the accident. Heavy equipment were being used to lift parts of the train and recover more bodies that are likely stuck in between train parts. At least two people were killed and nearly 100 passengers injured last June in the Indonesian capital after two commuter trains collided during the evening rush hour. --SP 21 11 Local Time 18 11 GMT