A third explosion has erupted inside the Pike River Coal mine in New Zealand where 29 miners were killed in an earlier explosion two days back.

Pike River Coal chairman John Dow said the third blast was smaller than the earlier two and it would not affect plans to enter the mine to recover the dead bodies.

According to officials, high levels of potentially explosive methane gas is propelling the explosions inside the mine.

Rescue workers are installing a jet-powered engine to pump carbon dioxide, nitrogen gas and water vapour into the mine’s tunnels to expel oxygen that could fuel more explosions.

Once the operation is completed, rescue teams will be able to enter the mine with breathing apparatus.

The first blast at the site occurred on 19 November, followed by a larger explosion on 24 November.