A book of condolences will be opened today from 14:00 to 18:00 at the Russian Embassy in Bulgaria to mark the nightclub tragedy in the Russian town of Perm in which 112 people died on Friday.

Russia is holding a day of mourning Monday for the 112 people killed in a nightclub fire in the city of Perm. Some TV programmes have been cancelled, flags are flying at half-mast and memorial services are being held across the country.

More than 140 people were injured, some seriously, when fireworks triggered the blaze in the early hours of Saturday.

Four people, including the club's owner, are in police custody while an investigation continues.

In Perm, residents have laid hundreds of red carnations outside the Lame Horse nightclub, which is surrounded by candles and photos of victims.

Many of those who died were trapped in the crush as more than 200 people fought to escape the smoke and flames through one narrow exit.