Rescuers searched yesterday for more than 30 Ukranian miners still missing 1,000m underground after a coal mine explosion that left 69 dead.
Another four bodies were recovered by emergency teams working through the night at the site in the industrial heartland of this former Soviet republic, the Ministry for Emergency Situations said.
Twenty-eight mine employees have so far been hospitalized.
President Viktor Yushchenko was expected to visit the site yesterday and three days of mourning were declared in the Donetsk region of eastern Ukraine.
The gas explosion occurred early on Sunday deep underground in one of Ukraine's largest coal mines, the Zasyadko mine, which has a long history of such disasters.
Relatives of those still missing endured a sleepless night gathered at the mine's headquarters awaiting news of loved ones, television news showed.
Many were overcome with emotion as officials periodically emerged to read out the latest names of the dead.
Several voiced disgust at the hazardous conditions the miners were subjected to for meager salaries, but said there was little alternative employment.
It took most of Sunday to localize the fire that swept through the mine after the blast, while rescue work was also inhibited by collapsed construction material, the Ukrainian Kommersant newspaper reported.
The paper said the explosion appeared to have been sparked by work to bore out a shaft that was intended to clear gas from the area concerned.
A massive rescue operation has been under way at the mine, where 456 people were working at the time of the incident.
The chief doctor attending the injured, Yevgeny Gadchuk, said the hospitalized miners were suffering from methane inhalation.
"They're in a state of shock," the doctor said.
Ukrainian Prime Minister Viktor Yanukovych, who comes from the region, was overseeing the government's response to the accident and promised to establish the cause.
President Yushchenko said in a statement before his visit: "I am grieving with all of Ukraine."
Ukraine's coal mines are concentrated in the eastern part of the country and are considered among the most perilous in the world, with many poorly financed and employing outdated Soviet-era equipment.
The Zasyadko mine, one of Ukraine's largest, employs some 10,000 people and produces up to 10,000 tonnes of coal every day.
It has gained a reputation as one of the most dangerous in the country.
In 1999 an explosion there claimed 50 lives, while in 2001 another blast left 55 people dead.
A gas leak in September last year killed 13 miners and made dozens more sick.
Most of the disasters were caused by build-ups of methane gas, which can occur suddenly in the mine shafts.
Wages at most Ukrainian mines depend on the volume of coal produced, which gives miners an incentive to ignore safety procedures that would halt work when methane levels are high, said Anatoly Akimochkin, deputy head of Ukraine's Independent Miners' Union.
"Everyone tries not to pay attention to small problems in the safety equipment," Akimochkin said. "The pay system is one of the biggest causes of our accidents."