The death toll at the site of an explosion at an Indonesian coal mine earlier this week has increased to 28 as more bodies were recovered today.

Officials said about a dozen others were still trapped in the 150m shaft and feared dead as they had no access to ventilation or safety equipment following the methane gas explosion at the mine, operated by private coal company PT Dasrat Sarana.

Nine workers who suffered serious burns were admitted to hospitals following the explosion on Tuesday, according to local news reports.

The explosion sent flames up to 50m high, leaving a huge hole in the mine.

The use of open-pit mining rather than underground mining has been blamed for the accident.