Employees of the Ruse-based arms and ammunition manufacturer Dunarit are set to stage a protest on Friday over the government's decision to scrap the plant's license over a "threat to national security."

The Danube Bridge, a key thoroughfare connecting Bulgaria and Romania and linking the cities of Ruse and Giurgiu, is to be blocked for an hour between 13:00 and 14:00 EET (11:00-12:00 GMT). The bridge is one of the only two between Bulgaria and its northern neighbor, the other being hundreds of kilometers to the west.

Dunarit is now prevented from exporting its production as well as importing raw materials, and its personnel say failure to deliver on contracts may result in a hefty forfeiture.

Trade unions had previously threatened to organize a strike unless the cabinet revokes its decision, though the demonstration set for Friday does not amount to strike action.

Ministers, however, are not inclined to do so, and Economy Minister Bozhidar Lukarski has suggested that Dunarit's output could be sold through "intermediaries" instead.

No government official has yet elaborated on the reasons to terminate Dunarit's license for four months, but in Lukarski's words the move was aimed at preserving the "financial stability" of Bulgaria.

The plant employs 750 workers, and trade unions fear they could soon be left unemployed.