Rescuers choking on fumes put out the blaze Thursday in dozens of train cars carrying fuel and chemicals that derailed and exploded in northern Iran, while the province's governor said 309 people were now confirmed dead in the tragedy.

Bulldozers and cranes were used to sort through the debris of villages and train wreckage 20 miles east of Neyshabur (search). Emergency workers collected human remains torn by Wednesday's blast, which was so powerful it devastated five villages, collapsing mud homes.

Burning freight cars from the derailment were put out shortly before dawn Thursday, with firefighters persisting through the night despite freezing temperatures and fumes. The explosion left a crater about 50 feet deep.

In Neyshabur, stunned residents came out for the funeral of their governor, Mojtaba Farahmand-Nekou (search), who was among several city officials, including the fire chief, killed when the train cars exploded hours after the derailment.

More than 20,000 mourners, all wearing black, looked on as the body, wrapped in the red, white and green Iranian flag was driven through the city.

Shops and offices closed for three days of mourning. Survivors looked through lists of the dead posted outside hospitals and clinics.

Alireza Babaie, who was in his 70s, was looking for the name of a friend who was coming to visit him from the provincial capital, Mashhad (search).

"His family said he was on his way, and he should have reached here by now. I don't know where he is, and I hope to God he is not among the dead," said Babaie, who was in his 70s.

Hassan Rasouli, governor of Iran's northeastern Khorasan (search) province, told reporters 309 bodies had been recovered by midday Thursday. He said 460 people had been injured.

The explosion occurred hours after runaway train cars carrying fuel, industrial chemicals and cotton derailed, overturned and caught fire in northeastern Iran. The blast was so large that windows in homes as far as six miles away were shattered.

In an apparent indication of the explosion's force, Iranian seismologists recorded a 3.6-magnitude tremor in the area at the moment of the blast.

Police sealed about a half-square-mile area around the blast scene near Neyshabur, a historical city home to 170,000 people about 400 miles east of Tehran.

The clay-home village of Dehnow, which was closest to the blast at about 500 yards away, was flattened and many Dehnow residents were believed to have been killed. The rest appeared to have been evacuated.

Shortly after the explosion, black plumes of smoke and orange flames billowing into the sky from the cars, 17 of which were loaded with sulfur, six with gasoline, seven with fertilizer and 10 with cotton. Dozens of people, some wearing face masks, were walking in the area or putting out flames.

Authorities were investigating what caused the 51 cars to roll out of the Abu Muslim train station at 4 a.m. local time. Forty-eight of the cars derailed on reaching the next stop at Khayyam, about 12 miles away, and caught fire.

Firefighters had extinguished 90 percent of the fire when the cars exploded, Mohammad Maqdouri, head of the local emergency operations headquarters, told Tehran television.

Eighty percent of those injured were hurt when their homes collapsed, and the rest were either burned or hurt from the force of the explosion, said Syed Majid Taqizadeh, head of the 22 Bahman hospital, named after the date in the Iranian calendar that coincides with Iran's 1979 Islamic Revolution.

Most of the injured were from the village of Hashemabad, Taqizadeh said. Other victims were found in Dehnow, Abdolabad and other nearby villages.

Hashemabad resident Zahra Rezaie, 41, said the she thought the blast was an earthquake.

"It knocked down and broke some dishes. I was sure it was an earthquake, and my first thought was to rush to the school and save my children," said Rezaie, who was cooking lunch for her family when she heard the explosion and felt the ground shake.

Neyshabur is at the center of a farming region for cotton, fruit and grain. It became one of Persia's foremost cities in the 400 A.D., a center of culture with several important colleges. Omar Khayyam (search), the 11th century Persian poet, was born in Neyshabur, and is buried there.