Protesting workers at the Babino pit, Bobov Dol mine, have been denied payment of salaries unless they sign an agreement with their employer, private NOVA TV station has announced.

Bobov Dol mines, owned by controversial entrepreneur Hristo Kovachki, employ 1800 people. Some 600 work at Babino, which was facing closure, but Kovachki withdrew its decision after the underground sit-in went into its second day on Wednesday.

Well into the third day, a number of protesters have come out of the pit, having spent more than 48 hours inside and suffering from nausea or other problems.

A representative of the management told workers on Thursday all people employed at the Bobov Dol mines will receive their salaries for August, except for those at Babino who must sign the agreement first.

Bobov Dol miners have been waiting for two months' salaries (some not having received the entire amount for previous months) and for food vouchers since March.

A lawyer for the mine operator earlier said that on Wednesday Babino workers were offered th receive remuneration only for August in case they ended the protest. The proposal was turned down, with demonstrators insisting they would not abandon the sit-in before being paid.

The management also insists that payment for August (and not for September) was due between October 05 and 10.

The Energy Ministry, which granted a concession on the mine in 2006 (the concessioner passed it over to Kovachki a year later), refuses to step in as it considers the development to be a private dispute between employees and the employer.

The labour inspection agency, however, demanded that salaries be paid immediately.

Bulgaria's national ombudsman, Maya Manolova, is expected to arrive to Bobov Dol later on Thursday.