By Alex Kirby
BBC News Online environment correspondent
A central Asian country says it cannot afford to replace an earthquake warning system which has proved its worth.
Tajikistan: A fault runs through it
Tajikistan's system, which is said to have predicted a 1989 earthquake, was destroyed in the country's civil war.
The system, which measures pressure and temperature changes in the ionosphere, provides up to two weeks' warning of an earthquake, a seismologist claims.
But the $2m needed to rebuild it cannot be found, raising concerns about the country's readiness for big tremors.
The seismologist is Professor Sobit Negmatullayev, a member of Tajikistan's Academy of Sciences and director of the country's Institute of Seismology and Earthquake-proof Construction.
He was speaking to BBC News Online in the Tajik capital, Dushanbe.
Professor Negmatullayev's prediction method is based on "disturbed equilibrium of pressure and temperature functions... in the atmosphere" and effects higher up in the ionosphere, he says.
The ionospheric effects are said to be explained by "heating by electric fields whose occurrence is associated with the last stage of the preparations for the earthquake in the Earth's crust".
Lake Sarez: Fewer worries
Many British seismologists are sceptical that any attempt to predict earthquakes can work, but Professor Negmatullayev says his method has proved itself.
He said: "In January 1989 there was a tremor in Hissar in Tajikistan which left 272 people dead - killed not by the earthquake itself, but by the landslides it set off.
"Two weeks before it struck we predicted that something would happen. Two days beforehand we predicted that it would not be catastrophic - and it wasn't.
"A big fault runs through Tajikistan, and all our main cities and power stations are above it.
"Earthquakes in Dushanbe tend to occur on a cycle of from 80 to 130 years. The last one here was in 1907, and tension is building up, so it's due for another one any time soon.
Withering on the vine
"The 1907 quake measured 7.4 on the Richter scale, and we estimate that the next one could kill thousands of people.
"It would cost up to $1bn to rebuild the city afterwards. But we could repair our measuring equipment, which was destroyed in the civil war between 1992 and 1996, for about $2m, if we could raise it.
"That would give the city two weeks' warning. But there's been no funding for science here since the break-up of the Soviet Union.
Dawn over Dushanbe: Thousands "could die"
"This institute and the Institute of Geology are the only two from 22 in the Academy of Sciences that are still functioning.
"In the others, people just don't bother to turn up for work. Every computer we use has been given to us by private donors or by the US or Canada."
Dr Brian Baptie, of the British Geological Survey, told BBC News Online: "Earthquakes are quasi-random events, and it's very hard to predict when they'll occur, and whereabouts on the faultline.
"In general no-one has ever successfully predicted one, and I haven't heard of anything like this working convincingly."
Professor Negmatullayev said earlier worries that Lake Sarez, in the Pamir mountains of south-eastern Tajikistan, could overflow and cause a catastrophic flood were greatly exaggerated.
The number of people thought to be at risk if it overflows has been reduced from several millions to below 50,000.