A passenger train derailed Thursday night while traveling from Istanbul to Ankara, the Turkish capital, killing at least 36 people, according to Turkish health officials.

Bodies and body parts littered the countryside near the town of Pamukova, 113 miles southeast of Istanbul, where four passenger cars flew off the rails, two of them crashing into each other after derailing. Turkish soldiers and local residents scrambled through the wreckage in the gathering darkness, covering remains with plastic sheeting and prying open jammed doors in a largely futile search for survivors.

"According to preliminary reports, 36 died, 60 were wounded and 45 survived the train crash," said the provincial governor, Ayhan Cevik, according to the semi-official Anatolian news agency.

Inaugurated June 4 by Prime Minister Recep Tayyip Erdogan, the train was operating as a high-speed link between Turkey's commercial center of Istanbul and the country's busy political capital. But the train had few of the high-performance technological attributes that the term high-speed implies.

It ran on ordinary railroad tracks, but at increased speeds intended to trim the roughly 250-mile trip from at least eight hours to less than five. The goal was to provide a travel option more affordable than driving and roughly equal in time to commercial flights, counting travel to and from airports.

But critics warned that simply increasing the speeds was perilous.

Aydin Erel, a professor of transportation science at Istanbul's Yildiz Technical University, was among the experts who had warned that "to make an Istanbul-Ankara trip in five hours a train has to make 160 kilometers an hour, which has a high risk of accident. The vibration and the force the train will put on the rails may cause the vehicle to derail.

"I have worries about the security," Erel said in remarks quoted July 14 in Turkish newspapers. "There are accident risks."

But railway officials insisted that the train was not traveling at an increased speed in the stretch where the accident occurred. Ali Kemal Ergulec, deputy director of the state railways, told reporters that a conductor who survived the crash said the train was traveling at a normal speed at the time of the accident.

"It's definitely not speed-related," Ergulec said.

Some surviving passengers told a different story in interviews at the scene.

"Obviously the fast train was going fast and the train collapsed," Serap Yavuz, who escaped through a window, told the television channel CNN Turk.

"I think this whole thing was a big gamble," another survivor, Orcun Acabey, told the Turkish-language news channel NTV.