Copper prices rose to a 10-day high on Thursday, supported by a break above key technical levels and potential supply risks related to a strike at BHP's Escondida mine, but trading volumes remained low as fund investors stayed on the sideline.

Three-month copper on the London Metal Exchange (LME) reached $9,088 per metric ton earlier in the day, breaking both 200-day and 21-day moving averages. It was trading up 1.2% at $9,083 as at 1028 GMT.

"Turnovers for copper and aluminium were significantly lower," senior base metals strategist Alastair Munro told Reuters.

Copper rallied to an all-time high in late May fuelled by speculation, but many funds have retreated and switched to gold and oil from metals, he said.

Trading volumes so far this week for copper were at 58,714 lots, compared to 180,788 lots for the week up to May 17.

Focus was also on potential disruption to supply in Chile.

Union workers at Escondida, the world's biggest copper mine, rejected operator BHP's request to pause their strike. BHP is yet to disclose any estimate on the impact on production.

Munro said it would take time for the market to factor in any potential significant drop in physical supply from the strike, Munro said.

LME aluminium rose 0.8% to $2,347 a ton, lead increased 2% to $2,049, zinc edged up 1.6% at $2,758.5, tin advanced 0.6% to $31,620 and nickel was up 0.8% at $16,400.

(Reporting by Julian Luk in London; Editing by Emelia Sithole-Matarise)