A THIRD EXPLOSION HAS struck the Pike River mine on New Zealand’s south island a week after the initial blast which trapped 29 men, the New Zealand Herald reports.

Pike River Coal chairman John Dow said nobody was injured in today’s blast, which occurred just five minutes short of the time of last Friday’s explosion.

A second explosion at the mine two days ago is believed to have killed all 29 miners.

Police said that “based on that explosion, no one survived”.

John Dow said that plans for the families of the deceased miners to be taken to the mine tomorrow are still in place, but they will not be taken to the mine portal or any unsafe areas.

The explosions are believed to have been caused by a build-up of gases inside the mine, which the Sydney Morning Herald says was beset by problems and safety issues since it first began operating.

Dow says this third explosion will not affect recovery efforts, while the BBC reports that New Zealand’s prime minister John Key has conceded it may take months to recover the miners’ bodies.

Emergency crews have been unable to enter the mine due to the dangerously high level of combustible gases inside, according to the BBC.

A third robot which entered the mine to video damage inside has recorded damage which hadn’t been videoed by the first robots, says Pike River CEO Peter Whittall.

Whittall says this video footage indicates the second blast was much more violent than the first explosion.

The following NZ Herald video shows the first footage collected by a robot inside the mine: