A bomb blew apart a subway car packed with rush hour commuters Friday morning, killing 39 people and wounding more than 130 in the deadliest terrorist attack in Moscow since Russia launched its second war in Chechnya (search) in 1999.

President Vladimir Putin (search) blamed Chechen separatists, although it was unclear whether the blast was the work of a homicide bomber or someone who merely placed a device on the train as it left the station.

"Russia doesn't conduct negotiations with terrorists — it destroys them," Putin said, adding that the attack appeared aimed at sowing discord before next month's presidential election.

There was no immediate claim of responsibility, but Chechen insurgents are blamed for a series of suicide bombings in Moscow and elsewhere in Russia. The blast came only three weeks after one of Chechnya's most feared warlords threatened fresh strikes in Russia.

The attack was not the first in Moscow's famed subway — renowned for its reliability and grandeur in an otherwise bleak and inefficient city — but it was the bloodiest. At peak periods, trains arrive every 90 seconds, roaring into stations adorned with chandeliers, mosaics and sculpture.

The bomb, which Deputy Mayor Valery Shantsev said contained the equivalent of 11 pounds of TNT, tore through the subway car after it left the Avtozavodskaya station and headed for the busy Paveletskaya stop.

It shattered windows throughout the train and left the targeted car a hulk of twisted metal. Bodies still sat side-by-side on the seats, covered in soot. Other bloodstained corpses, their clothes torn, lay along the tracks.

Deputy Interior Minister Alexander Chekalin said 39 people were killed and 134 wounded, including 113 who were hospitalized.

The seriously wounded were carried on stretchers through the tunnels deep beneath the streets of the capital and into the marble-walled station, then up the long escalators to the surface and waiting ambulances.

More than 700 people were evacuated from the two stations, the ITAR-Tass news agency reported.

"I heard a loud sound like a large firecracker and smoke filled the car," said Ilya Blokhin, who was riding several cars away from the blast. "What are our country and government and police going to do when they blow up crowded subway cars?"

A woman identified only as Maria, her face covered in blood, told Russian TV that for a long time after the explosion, passengers were unable to open the door of the subway car. After prying the door open, she said they walked out of the tunnel.

The Moscow Metro is the world's busiest subway with an average 8.5 million passengers a day, and has long been seen as especially vulnerable to terrorism. Police routinely stop people in the stations who appear to be Chechens or from the North Caucasus area, but crowds make thorough surveillance impossible.

The Interfax news agency cited unidentified police officials as saying that a suicide bombing was the "main working version" to explain the attack.

Police have a videotape of a woman suspected of being the bomber and her alleged accomplice standing on the platform of the station before boarding the train.

But Shantsev said investigators had not found any shrapnel, which usually fills suicide bombers' explosives, and that the bomb had likely been in an attache case or backpack on the floor of the subway car.

Russia has been fighting an insurgency in Chechnya for most of the last decade.

Putin, who is expected to win the March 14 presidential elections handily, has built much of his strong image on a firm refusal to negotiate with the Chechen rebels.

He linked the attack to Aslan Maskhadov, who was elected Chechen president after Russian forces withdrew in 1996 at the end of a disastrous 20-month war against separatist rebels.

"We know for sure that Maskhadov and his bandits are linked to this terror," he said.

Maskhadov's foreign envoy, Akhmed Zakayev, denied the Chechen leader was involved.

Warlord Shamil Basayev has claimed to have masterminded some of the most recent terrorist acts in Russia. In January, a Web site that is a rebel mouthpiece cited him as saying more attacks were in the works.

President Bush phoned Putin to express condolences, and U.S. Ambassador Alexander Vershbow offered assistance. Condemnations also poured in from European capitals and former Soviet republics.

In December, a homicide bomber blew herself up outside the National Hotel across from Moscow's Red Square, killing at least five bystanders. Two homicide bombers blew themselves up at a Moscow rock concert last July, killing themselves and 14 other people. Five days later, an aborted homicide bomb attack at a Moscow restaurant killed a disposal expert who was trying to defuse the bomb.

A bombing in a Moscow subway car in 1996 killed four people; in 2000, a bomb exploded at a pedestrian underpass filled with kiosks at Pushkin Square, the site of three subway stations.

The deadliest terrorist bombings in Moscow occurred in 1999, when more than 150 people were killed in two apartment house blasts. Those explosions were among the events that prompted the Kremlin to launch the second military campaign in Chechnya.

In October 2002, 129 hostages died when Chechen rebels stormed a Moscow theater, almost all the victims died from the knockout gas that Russian forces pumped into the theater to end the siege.