(Adds details from Codelco, comment from Antofagasta, and context)
SANTIAGO, March 26 (Reuters) - Chile's Codelco, the world's No. 1 copper producer, said on Thursday it is gradually reopening mines in the north of the country that were closed on Wednesday due to heavy rains, but that its Salvador mine remained shuttered.
Conditions at Salvador did not yet permit safe operation, and 17 workers were stranded at the site, but had access to shelter, food and communications, Codelco said in a statement.
Torrential downpours in northern Chile since Tuesday have flooded towns and made roads impassable, forcing a number of mining companies to suspend operations.
The worst hit region has been Atacama, where villagers are being evacuated by air.
Mines in Atacama include Salvador, Anglo American's Mantoverde, and JX Nippon Mining & Metals' Caserones.
Operations at all of them were suspended on Wednesday.
London-listed Antofagasta Minerals said in a tweet on Thursday morning that its Centinela, Michilla, and Antucoya mines will still closed.
Codelco said that due to the state of roads it was not transporting sulphuric acid or flammable materials to some mines, but they had sufficient supplies in stock to continue operating.
Reporting by Rosalba O'Brien; Editing by Peter Galloway