The signal received Tuesday evening about a bomb threat at the upscale hotel "Kempinski Zografski," was hoax, the Interior Ministry informs Wednesday.

The authorities further say that search for explosives at the hotel is over, but the building might remain closed for 24 hours, a decision that needs to be made by the hotel management.

All guests, mainly foreigners, were evacuated Tuesday evening and accommodated at the nearby “Hill” hotel. The staff provided blanket and drinks while they were waiting outside. The management is verifying if guests can be accommodated at other upscale hotels in Sofia.

Police has checked all rooms and common areas and did not discover anything suspicious. The hotel has 180 standard rooms with views of the Vitosha mountain or the city, 244 luxury rooms, 15 apartments, 2 vice-presidential and 1 presidential suites.

The anonymous phone call to the Sofia Police Directorate was made around 6:55 pm and a male voice reported there was a bomb at the hotel.

All guests and hotel staff were immediately evacuated and the area sealed off.

Authorities are investigating the case.