Hitrino (Bulgaria) (AFP) - Seven people were killed and dozens were injured on Saturday when a freight train carrying highly flammable gas derailed and then exploded, devastating a village in northeastern Bulgaria.
A blast ripped through the centre of the village of Hitrino, destroying a railway station, offices and dozens of houses and sending plumes of black smoke into the air, an AFP photographer saw.
The head of the Bulgaria's civil defence organisation, Nikolai Nikolov, said the death toll had risen to seven.
"We are no longer looking for people in the rubble," he said.
Health Minister Petar Moskov said 29 people had been hospitalised, nine of whom were in a critical condition, and 23 others suffered lesser injuries.
Authorities have warned the death toll may yet rise.
Local environment inspectors said that except for fine particles, air pollution in Hitrino late Saturday was below emergency levels as gas and carbon dioxide had been dispersed by the wind.
The freight train, which derailed while entering the station, was hauling 20 tankers of highly-flammable propylene gas as well as four containing liquefied petroleum gas, a mixture of propane and butane.
The last two tankers hit a power line and exploded, with seven tankers full of propylene going off the tracks, local police spokeswoman Assia Yordannova said.
The blast occurred at 5:37 am (0337 GMT), causing devastation to a huge area of this small village which has a population of around thousand, located about 100 kilometres (60 miles) from Varna, Bulgaria's main port on the Black Sea.
A passenger train was just about to enter the station when the accident happened.
"All buildings within a radius of 200 metres from the tracks are ruined, burned down," an AFP correspondent at the scene said.
He said firefighters and rescuers were working to cool off the tankers scattered along the railway tracks while searching for survivors under the debris.
The interior ministry said about 200 people were involved in the rescue efforts.
- Derailments common -
Aerial footage showed a massive plume of black smoke rising over the village and charred tankers lying scattered around the tracks by the ruined station.
One whole block of houses near the derailed tankers was gutted and there was smothering debris everywhere.
By midday (1000 GMT), the fires which had raged since the early hours had been put out, and officials began evacuating residents as firefighters and experts from the nearby Lukoil Neftochim oil refinery prepared to pump out the remaining gas from the tankers.
Examining the damage, Prime Minister Boyko Borisov called for a day of national mourning on Monday and appealed for solidarity and blood donations to the hospitals treating the injured.
Local residents said the firefighters had been very slow to arrive and many broke down in tears while recounting how their houses collapsed.
Accidents involving freight trains are relatively frequent in Bulgaria where railway tracks are obsolete and regularly looted by thieves. But fatalities are rare.
- Drivers survived -
Investigators from the capital Sofia were dispatched at the scene to probe the causes of the accident which occurred as the train was en route from the Black Sea city of Burgas to neighbouring Romania.
Stanko Stankov, head of train operator Bulmarket, said his company only operated the engines, while the tankers were owned by a Romanian firm.
He said there were three drivers on board at the time, and all of them had survived. Officials said investigators had spoken to all three.
Propylene is an extremely flammable but non-toxic gas which burns much hotter than propane butane.
On January 23, eight carriages of another freight train derailed at high speed while passing near the southwestern town of Dupnitsa.
There were five derailments in both 2014 and 2015, with the causes varying from rocks on the tracks to parts looted from railway junctions.