LONDON: Copper prices touched a five-month peak on Friday on growing fears that output will be disrupted in top producer Chile by worsening COVID-19 infections at mines.

Chile's Codelco, the world's biggest copper miner, suspended refinery and foundry operations at its Chuquicamata division to prevent further spread of the new coronavirus.

"Chile has been one of the fortunate producers. It hasn't suffered too much from the outbreak and government lockdowns didn't really have much of an impact on production in the first four months of the year," said Kieran Clancy, assistant commodities economist at Capital Economics.

Three-month copper on the London Metal Exchange had climbed 1% to $5,952 a tonne by 1600 GMT, the strongest since January 24. It was on track for a 1.8% weekly gain, its sixth straight weekly rise.

The spread between LME cash copper and the three month contract flipped to a premium for the first time since April last year, indicating worries about short-term supply. It was at a premium of $1.15 a tonne on Friday compared to a discount of $30 on June 16.

LME aluminium stocks extended their rise, adding 14,275 tonnes to 1,652,025, the highest since April 2017, having shot up 70% since mid-March, LME data showed.

LME aluminium shrugged off the signs of surpluses, jumping 2% to $1,601 a tonne.

LME zinc shed 0.2% to $2,045 a tonne, nickel gained 2% to $12,690, lead edged up 0.03% to $1,786.50 and tin rose 1.6% to $16,850.