JOHANNESBURG (AP) — Cellphone video of last year's massacre by police during a strike outside Lonmin's platinum mine in Marikana, South Africa shows one police officer warning colleagues not to shoot before others opened fire, killing 34 miners.

The video raises questions about whether the shootings were in self-defense, as police have categorized them.

Ian Farlam, the chairman of the commission overseeing hearings on the deaths of the miners on Aug. 16, said Tuesday it is premature to draw conclusions from the footage. Farlam did confirm that two policemen filmed the footage broadcast by Britain's Channel 4 on Sunday.

Another portion of the cellphone video shows an officer calling a miner an expletive, and then saying: "I shot him at least 10 times."

The video was filmed on Aug. 16, the day that police killed 34 miners. It was submitted to the commission investigating violence during nearly six-weeks of protests at the Marikana mines that killed 46 people in total and sparked labor protests across South Africa. Farlam said the footage was seen by the commission in November.

The video shows how police kept their guns trained on two men while they crawled through a field. It shows a tactical response team officer calling for restraint while a miner is on the move.

"The guy is there running. Wait. Don't shoot him, don't shoot him," the officer shouts.

However, gunshots are heard and then the camera moves over the lifeless body of a man.