FILE PHOTO: A Bitcoin logo is seen on a cryptocurrency ATM in Santa Monica, California, U.S., January 4, 2018. REUTERS/Lucy Nicholson

DUBAI (Reuters) - Iranian authorities have seized about 1,000 bitcoin mining machines in two abandoned factories, state television reported, after warnings that the activity had led to a spike in consumption of government-subsidized electricity.

“Two of these bitcoin farms have been identified, with a consumption of one megawatt,” Arash Navab, a power official in the central province of Yazd, told the television.

The machines, which produce cryptocurrencies that are banned in Iran, were mostly to blame for a 7% increase in power consumption in the month to June 21, according to an Energy Ministry spokesman, quoted by the website of state-run Press TV.

In 2018, Iran’s central bank banned the country’s banks from dealing in cryptocurrencies, including bitcoin, over money-laundering concerns.