A subway fire that killed more than 125 people is forcing officials to strengthen safety measures on trains after a suicidal man who said he did not want to die alone ignited the blaze in a train stopped at a station.

A second train arrived at the station minutes later and was engulfed in flames, raising concerns about why it wasn't diverted or stopped.

Critics said Tuesday's tragedy in South Korea's third-largest city revealed problems with the nation's emergency response system and a potential vulnerability to terrorism.

"This incident shows we have a big hole in our social safety measures," said an editorial in the Chosun Ilbo daily newspaper. "This shows that we don't have protection from possible terrorist attacks."

The suspect, Kim Dae-han, 56, has a history of mental illness and was trying to commit suicide, police said. Kim told police "he decided to die with others in a crowded place, rather than die by himself," said police Lt. Cho Doo-won.

Closed circuit television footage released Wednesday showed the fire starting, with a man -- believed to be the suspect -- running from the train carrying a burning object.

Passengers scattered and the station could be seen immediately filling with smoke.

The disclosure of a possible motive for the fire came as criticism mounted of officials.

Had the train been equipped with fire-resistant seats and floor tiles, many said, it probably would not have burst into flames. And an apparent lack of emergency lighting left victims groping in the dark after the lights went out.

Grieving relatives of victims complained of delays in identification of the bodies.

Officials with the subway system, which carries 6.5 million passengers daily, responded with promises to install emergency lighting, increase the number of exit signs, make car interiors flame-resistant and heighten security.

The city government also said it would increase the number of security guards, set up security cameras and quickly run a series of fire drills in subway stations.

By late Wednesday, only 44 of the dead -- many burned beyond recognition -- had been identified, and officials feared more of the 145 injured might die.

Authorities counted 350 people listed as missing, but said the number was inflated by double reporting and confusion over the identities of the dead.

President Kim Dae-jung designated Daegu a "special disaster area," giving tax breaks and financial aid to victims and businesses.

Sobbing relatives of the dead scuffled with police as Prime Minister Kim Suk-soo visited the site of the fire.

"The government is not hurrying up with the investigation," Kang Mee-ja, whose mother died in the attack, cried as she looked at the charred remains of the subway cars. "As her daughter, I just want to bury her quickly."

Relatives of the missing were permitted to see the wreckage, which had been towed to a train depot on the outskirts of Daegu. Near the attack site, other family members piled bouquets of chrysanthemums on a makeshift shrine in honor of the victims.

Subway officials were being interrogated by police. A key question was why the second train was permitted to arrive at the station minutes after the first train erupted in flames.

One officer, who spoke on condition of anonymity, said the fire crippled the subway communication system and authorities apparently could not warn the second train -- which accounted for most of the deaths.

"We call for a thorough investigation of whether subway authorities failed to respond quickly and properly when the fire first broke out," the Joongang Ilbo newspaper said.

Witnesses said the suspect used a cigarette lighter to set fire to a container filled with gasoline or another flammable liquid. Some passengers tried in vain to stop him.

The suspect was hospitalized with light burns. After the attack, police said he refused to answer questions and spoke incoherently. He had once threatened to burn a hospital where he received what he considered unsatisfactory treatment, local media reported.