A big explosion has ripped through a block of flats in Moscow killing at least one person. Emergency workers say they fear up to 17 people could be trapped under the rubble on Akademik Korolyov Street near the Ostankino television tower. Emergency teams with sniffer dogs are frantically working to find survivors in the darkness. Officials say they believe the explosion was caused by a gas leak, although a number of residents report smelling gun powder, not gas, after the blast.

The BBC's Steve Rosenberg in Moscow says the scenes of destruction have brought back painful memories for many Muscovites, three years after a series of terrorist explosions in apartment blocks in Moscow and southern Russia left hundreds dead.

President Vladimir Putin has despatched the Emergencies Minister, Sergei Shoigu, to lead the rescue effort.

'Column of smoke'

Reports say the explosion occurred at 2310 local time (1910 GMT) in one of the entries of the building, which is of old-fashioned design.

It ripped a hole 10 metres (10 yards) wide down the length of the building

A Russian journalist working for NTV television described the nightmarish scene:

"Numerous teams of rescuers, fire-fighters and ambulance workers are being deployed here now.

"Sirens are wailing non-stop. A column of smoke has not settled yet. It is very difficult to breath. The debris is still smouldering."

One survivor said she saw her son fall through the floor.

The injured include burns casualties although there is no major fire burning at the scene.

PHOTO CAPTION

Two emergency officials look at debris after an explosion in a residential building in Moscow, Wednesday, Aug. 21, 2002. Part of a residential building collapsed in an explosion in the north of Moscow late Tuesday, leaving a 49-foot-wide hole down the length of the house. At least one person was killed, police said, and emergency officials feared up to 25 people could be trapped in the wreckage. (AP Photo/Alexander Zemlianichenko)