SURABAYA • A large sinkhole appeared in the middle of a busy road in the city of Surabaya in East Java province on Tuesday evening, swallowing part of the four-lane Jalan Raya Gubeng.

The sinkhole measured about 30m wide and 15m deep.

The police have cordoned off the area and detoured traffic.

East Java police chief Lucky Hermawan said there had been no reports of any injuries in the incident.

Thousands of vehicles use the Surabaya road daily, taking some takes five minutes to travel the entire length of Jalan Gubeng. But now the same distance will take them roughly an hour.

Motorist Rudianto, 47, said he saw trees and lampposts swaying by the roadside just before the incident.

"I thought it was an earthquake. I backed the car and went against the flow. People ran around asking for help, leaving their vehicles," he added.

National Disaster Mitigation Agency spokesman Sutopo Purwo Nugroho said the sinkhole was caused by a construction error. "The retaining wall was not able to withstand the load, especially during the rainy season," he said.