Two trains collided on the main island of Java in Indonesia today, Friday, resulting in the carriages crashing and overturning and killing at least four people.

Eyip Hanapi, spokesperson for PT Kereta Api Indonesia, the national railway company, said the accident occurred about 500 meters from Cikalangka train station in West Java province.

He added, "The Turanga express train carrying 287 passengers was traveling from Surabaya, the capital of East Java province, when it collided with a passenger train in Bandung Raya with 191 passengers heading to Padalarang from Horbojogor station at around 6:03 am."

Hanapi continued: "All passengers of the two wrecked trains were evacuated safely," adding that 37 people were injured and treated in several hospitals, and by Friday afternoon, only two passengers remained in the hospital.

Passenger Hery Alidin said the lights went out in his carriage in the third carriage of the Turanga train, noting that bags and luggage fell on many passengers, and those who were still asleep fell from their seats.

Alidin told Kompas TV in an interview: "I felt a severe shock, I couldn't move for a moment, it was total confusion, then I grabbed my bag and pushed my way out."

West Java police spokesperson Ibrahim Tombo said at least four train crew members were killed, including the driver and his assistant on the passenger train, a conductor, and a security guard on the express train.

Several carriages were shown flipped over or severely damaged in television footage, with one carriage falling into a nearby rice field, while people screamed as terrified passengers tried to get out of the train, and some walked through fields carrying suitcases and other items as ambulances evacuated the injured.

Spokesperson for the Ministry of Transportation, Adita Irawati, apologized for the accident and the disruption of railway services across the island of Java.

She added that the cause of the accident is under investigation and that rescue workers evacuated all passengers and are working to remove the trains to restore service.

Irawati added: "This accident will be subject to further evaluation so that a similar accident will not occur again in the future."

Major local media reports stated that a preliminary investigation concluded that the passenger train received the green light to proceed when the express train was almost at Cikalangka station, and usually, the passenger train stops at Horbojogor station to give way to the express train before continuing.

Dedik Hartanto, president director of PT Kereta Api Indonesia, was not drawn to comment on whether miscommunication was the cause of the accident, saying Hartanto: "We do not want to speculate before the investigation is complete, let's give time to the National Transportation Safety Committee to conduct a comprehensive investigation."

Train accidents are common on Indonesia's old railway network, especially at crossings.

In October 2013, a passenger train collided with a minibus carrying families of pilgrims at an unguarded crossing in Indramayu area in West Java, killing 13 people. In 2010, a train from the capital Jakarta collided with the rear of a stopped train at a station in Central Java province, killing 36 people.

The government has spent billions of dollars on improving infrastructure, including roads, railways, airports, and power plants, in the world's largest archipelagic country, which has more than 270 million people.

A $7.3 billion high-speed rail line, the first of its kind in Southeast Asia, began commercial operation in October, and the 142-kilometer (88-mile) railway line, a major project under China's Belt and Road infrastructure initiative, has significantly reduced travel time between Jakarta and Bandung from three hours to about 40 minutes.