YEREVAN, July 17 -- Armenia has placed a major industrial asset under state control after its owner, opposition leader Gagik Tsarukyan, was arrested on charges of financing mass public disorder, in the sharpest escalation yet of a government crackdown on the country's largest opposition party.

The AraratCement plant, one of Armenia's primary cement producers, was transferred to state management following an order from the Prosecutor General's Office. Authorities said the seizure was a precautionary measure tied to the criminal proceedings against Tsarukyan, whose assets are now subject to restrictions pending the outcome of the case.

Tsarukyan, the founder and longtime chairman of the Prosperous Armenia Party, was detained last week as ...