JAKARTA — Many of those killed and injured in a major earthquake on the Indonesian island of Java were children who were at school when it hit, rescuers say.

Aprizal Mulyadi, 14, said he was trapped after "the room collapsed and my legs were buried under the rubble".

He said he was pulled to safety by his friend Zulfikar, who then later died after becoming trapped.

The local administration in Cianjur says the death toll has risen to 252 people.

Earlier on Tuesday Indonesia's national disaster response agency, the BNPB, put confirmed deaths at 103 with 31 people missing, but warned this number was likely to rise.

The 5.6 magnitude quake struck a mountainous region on Monday, causing landslides that buried entire villages near the West Java town of Cianjur.

Victims were crushed or trapped after walls and roofs caved in. "It all happened so fast," Aprizal told AFP news agency.

A representative of the National Search and Rescue Agency also confirmed that many of the dead were young people.

"Most of the casualties are children because at 1 pm, they were still at school," said Henri Alfiandi.

The earthquake, which struck at a shallow depth of 10km, was followed by dozens of aftershocks which caused more damage to the area where poorly built homes quickly collapsed.

In the village of Cibereum, a family was trying to retrieve the body of their eldest son - a 28-year-old man who had been crushed to death when the other levels of the home fell on him.

Rescuers struggled to sift the rubble.

"We have to dig through the concrete of the second floor that crushed the victim. But we have seen the body," a military official, First Sergeant Payakun told the BBC.

Authorities say at least 2,200 homes have been flattened and more than 13,000 people evacuated.

President Joko Widodo visited the remote disaster zone on Tuesday where he was pictured with responders.

"My instruction is to prioritise evacuating victims that are still trapped under rubble," he said.

Authorities have deployed hundreds of police and other rescuers to the region to help the rescue effort.

Jokowi also pledged emergency resources and compensation to affected communities.

Earthquakes are common in Indonesia, which sits on the "ring of fire" area of tectonic activity in the Pacific.

The country has a history of devastating earthquakes and tsunamis, with more than 2,000 people killed in a 2018 earthquake on the island of Sulawesi. — Agencies