At least 162 people were killed and over 700 were reported injured in a shallow 5.6-magnitude earthquake that shook Indonesia's main island Java Monday.

"It is with regret that I convey this bad news. One hundred and sixty-two people died and 326 were injured, mostly with broken bones," Governor Ridwan Kamil told reporters.

More than 13,000 people were displaced and 2,000 homes were badly damaged, he said.

Earlier in the day, the National Disaster Management Agency said 25 people were still trapped under the rubble in Cianjur's Cugenang area.

Cianjur district chief Herman Suherman said at least 40 of the dead were children who were hit by collapsed buildings.

Earlier he said that some areas remained isolated because of landslides.

"Injured victims remain untreated in hospitals because there are not enough health workers."

Metro TV showed scores of people lying outside the Sayang General Hospital in Cianjur, some attached to intravenous drips.

Suharyanto, the head of the National Disaster Management Agency, said most of the victims were hit by debris from their collapsed homes.

"Many people died because their homes were unable to withstand the quake," he said.

Suharyanto said casualties could have been much higher if the quake had happened at night. "It happened during the day and many people were not at home," said Suharyanto, who goes by one name.

The tremor, which damaged buildings and triggered a landslide, was centered in the Cianjur region of West Java, according to the United States Geological Survey (USGS).

It was felt as far away as the capital of Jakarta, where panicked residents ran into the streets.

Broadcasters showed several buildings in Cianjur with their roofs collapsed and debris lining the streets.

Jakarta rattled

The country's meteorological agency warned residents near the quake to watch out for more tremors.

"We call on people to stay outside the buildings for now as there might be potential aftershocks," the head of Indonesia's meteorological agency, Dwikorita Karnawati, told reporters.

The USGS had earlier reported the quake's magnitude as 5.4.

There were no reports of casualties or major damage in Jakarta.

Mayadita Waluyo, a 22-year-old lawyer, described how panicked workers ran for the exits of their building in Jakarta as the quake struck.

"I was working when the floor under me was shaking. I could feel the tremor clearly. I tried to do nothing to process what it was but it became even stronger and lasted for some time," she said.

"I feel a bit dizzy now and my legs are also a bit cramped because I had to walk downstairs from the 14th floor."

Hundreds of people were waiting outdoors after the quake, including some wearing hard hats to protect from falling debris, an AFP reporter there said.

Indonesia experiences frequent seismic and volcanic activity due to its position on the Pacific "Ring of Fire", where tectonic plates collide.

A 6.2-magnitude quake that shook Sulawesi island in January last year killed more than 100 people and left thousands homeless.