We don't know whether they're alive or not

Baikonur duty officer

The eight had been working to repair the roof at the time, but fell through and were trapped under the debris, Deputy Emergency Situations Minister Gennady Korotkin said.

A specialist team of 30 rescue workers is being flown from Moscow to help recover victims and they are expected to arrive in Baikonur shortly.

Fear of collapse

However, Kairzhan Turezhanov, a spokesman for the Kazakh Emergency Situations Committee, said it was unlikely any would have survived the fall.

"We don't know whether they're alive or not," said a Russian duty officer at Baikonur.

The hangar has been cordoned off because of fears that the walls could collapse and local Kazakh rescuers were prevented from entering because of its instability, Mr Turezhanov said.

The BBC's Nikolay Gorshkov says Moscow has been short of funds to maintain the complex, and parts of it have fallen into disrepair.

The Russian Aviation and Space Agency has set up a special centre to investigate the causes of the incident.

World's oldest

The Baikonur cosmodrome, Russia's main commercial launch site, was built in the 1950s and is the oldest working launch site in the world.

The first man�made satellite to orbit the Earth was launched from here.

Baikonur is the world's oldest launch site

The Buran project was initiated in 1976 in response to the US space shuttle programme but abandoned after the collapse of the USSR. It completed one unmanned flight in 1988.

More recently, Baikonur has been used to launch commercial satellites and rockets bound for the International Space Station.

Kazakhstan took possession of the cosmodrome after the disintegration of the USSR. But it lacked the funds and expertise to maintain the site, which was looted by local people who sold sophisticated equipment for scrap metal, our correspondent says.

Russia has been leasing Baikonur from Kazakhstan since 1993, though the two former Soviet countries have on several occasions been at odds over rent payments and accidents during launches.