Three foreign workers have died in a site accident at the Simandou iron ore project in Guinea, its co-developer Winning Consortium Simandou said on Thursday, adding that it has suspended operations and launched a full safety review.

The incident took place at a WCS work site in Kerouane province, the Chinese-controlled company said.

Simandou, one of the world's largest untapped iron ore deposits, is being developed by WCS and Rio Tinto under close government oversight, with companies filing monthly progress reports, a source said.

It is aiming to meet a November deadline for first exports from the long-delayed mine. Missed production timelines will attract financial penalties, the source familiar with the matter added, as authorities push to commission the project.

'Supporting victims' families'

Officials of the Guinean government did not immediately respond to a request for comment.

Simandou is largely a Chinese venture, with 75% of the production controlled by Chinese companies including Baosteel , and 25% held by Rio Tinto, the world's largest iron ore miner.

WCS said it is supporting the victims' families and will only resume operations once safety conditions are fully guaranteed.