There was a fire at the portal of the Pike River coal mine just after 6.30am today.
The fire was the result of the PUR foam being used to seal the mine self-combusting and was unrelated to the fire burning inside the mine.
Experts at the site said self-combustion of this foam, when used in the quantities required at the mine portal, was not unusual.
The fire was extinguished and no one was hurt in the incident.
Some equipment is in place at the entrance to the mine and the sealant work is 90 percent complete.
Work to reassess and cool the portal has begun and sealing will resume once that is completed.
Deployment of the GAG will depend on the toxicity in the mine. Overnight reports show the gas readings remain extremely high.
Our experience over the past week shows the pattern of buildup of toxic gases during the day increase the likelihood of further explosion.