By Megha Rajagopalan and Michael Martina
BEIJING/TURPAN, China (Reuters) - China said on Wednesday it had caught five suspected Islamist militants after a vehicle burst into flames on Beijing's Tiananmen Square in what police called a terrorist attack.
Authorities also moved to tighten security in the restive far western, energy-rich region of Xinjiang, where the suspects are from.
The Xinjiang-registered SUV involved in Monday's incident in which five people were killed was driven by Usmen Hasan, police said, a man whose name suggested he is an ethnic Uighur, a Muslim people from Xinjiang.
His wife and mother were with him in the car, along with devices filled with gasoline, knives and a flag with "religious extremist content" written on it, police said on their official microblog.
The vehicle ploughed into pedestrians in the square, which has drawn occasional protests since 1989 pro-democracy demonstrations were suppressed by the military. Sources earlier told Reuters it was a suspected suicide attack.
"Police have identified Monday's incident at Tiananmen Square as a violent terrorist attack which was carefully planned, organised and premeditated," police said, adding the three people in the vehicle died after they set the gasoline on fire.
The other two people killed were tourists. At least 38 people were injured.
Five people connected with the incident were caught just 10 hours after the attack, with help from the Xinjiang government, the police added, all of whom also have names that suggest they are Uighur.
Police said they had seized Islamist militant flags and knives from where they were staying.
"As a common enemy of mankind, terrorism has no future, and is doomed to failure," state television said in a commentary on its microblog. "We firmly believe that the Communist Party and government have the ability and the power to resolutely beat back and defeat all illegal terrorist activities."
As authorities stepped up already-tight security in Xinjiang, Dilxat Raxit, a spokesman for the main exiled Uighur group, the World Uyghur Congress, warned against believing China's side of the story.
"Beijing has always made these kind of accusations, but they refuse to make public the reasoning behind them. They will not make the story behind the accusations transparent," he told Reuters.
Raxit said he was worried the incident would provide authorities with an excuse "to further repress Uighurs".
"If an attack is committed by a Han Chinese, it's not terrorism, but if a Uighur commits it, it is," he said, referring to the majority community. "Beijing makes these accusations in service of an ulterior motive."
The government denies accusations of repression.
It insists its respects the region's people and traditions and blames separatist Uighur militants for provoking violence in Xinjiang, which borders the Central Asian states of the former Soviet Union as well as Afghanistan and Pakistan.
Reuters reporters in Xinjiang were turned back by police at a roadblock outside Lukqun town, and sent back to the nearby city of Turpan.
Police have identified one of the caught suspects as being from Lukqun, where 35 people died in June in what China also termed a terrorist attack.
"We have some police matters we are handling. For security reasons, you are not allowed in. I imagine it will be at least another month or two before this area is open," a police officer at the checkpoint said.
In a small village near the checkpoint, a young Uighur man who declined to give his name said people were afraid.
"In the past few days, the police have been everywhere. At night, the sirens were all around. We are afraid to speak. If you speak, you will be taken away or shot," the man said, making a pistol shape with his hand.
Xinjiang is home to the Turkic-speaking Uighurs, many of whom chaff at China's controls on their religion and culture and there have been violent clashes there in the past.
But many experts, rights groups and exiles say China exaggerates the militant threat to justify its harsh rule, and that there is no cohesive separatist or extremist movement.
"The footage and photos that have been made available suggest a sense of randomness about the attack even though officials have said it was premeditated," said Michael Clarke, a professor at Australia's Griffith University who has studied Xinjiang.
"It's perhaps not as sophisticated as it's made out to be."
(Writing by Ben Blanchard; Editing by Robert Birsel)