Two oil tankers are burning 55 kilometers northeast of Singapore's Pedra Branca island, Bloomberg reports, citing the country's maritime and port authorities, as cited by Focus.
According to information from the agency, the tankers sailed under the flags of Singapore and Sao Tome and Principe.
A search and rescue operation involving a Singapore Navy ship and a military helicopter is currently underway. The authorities called passing ships for help.
The incident took place on one of the busiest sea routes in the world, which connects China, Japan and the Republic of Korea to the Middle East and Europe.