The blast - thought to be the country's worst mining disaster of the post-Soviet era - happened at on Saturday at the Barakova mine in the Luhansk region. The emergencies ministry said nearly 300 miners had been underground at the time of the explosion, but all have now been accounted for. Seven people were being treated for their injuries.

They had been working at a depth of 664m (2,000ft) when the explosion ripped through the mine.

"As far as I remember there has been nothing like this in the past 10 years. This is the biggest," Emergencies Ministry spokesman Oleh Bykov said.

Deadly methane

Naturally occurring gas Seeps out of coal seams Builds up in poorly-ventilated shifts

Rescue workers said coal-dust was likely to have increased the deadliness of the methane gas explosion.

Dozens of technical and medical back-up staff were rushed to the scene of the accident.

Official concern

More than 200 miners survived the explosion

Ukranian President Leonid Kuchma broke off his holiday and postponed a planned trip to Poland because of the incident.

And a spokeswoman said Prime Minister Viktor Yushchenko had decided to postpone a trip to the United States planned for next week.

He is expected to visit the mine on Sunday.

Common occurrence

Fatal underground methane gas explosions have been common in Ukraine's mines in recent years.

Troubled mines

May 1999 - 50 miners burnt to death April 1998 - methane explosion killed 63 Nearly 130 have died so far this year 1999 - about 280 died 1998 - about 360 died 1997 - about 260 died 1996 - nearly 340 died 400,000 coal workers More than 200 mines Average wage $100

The BBC's Senior Russian analyst, Stephen Dalziel, says shoddy working practices and low safety standards in Soviet times caused many mishaps.

And since it gained its independence in 1991, Ukraine has been too poor to devote the necessary resources to improving matters.

In one of the country's worst disasters, a methane gas explosion killed 63 men in a Donetsk mine two years ago.

About 50 miners burnt to death in an explosion in the same region in May 1999.

Ukraine has 400,000 coal workers and more than 200 mines, concentrated in the Donbass coal region in the east of the country.