BEIJING — The Chinese authorities announced yesterday the arrest of five people described as Islamist jihadists, who they say helped orchestrate what they labelled — for the first time — “a violent terrorist attack” on the political heart of the nation that left five people dead.

In a message posted on its microblog account yesterday, the Beijing Public Security Bureau said the men, all ethnic Uighurs from China’s western Xinjiang region, had enlisted a family of three to drive a vehicle across a crowded pavement on Monday and then ignite the car at the foot of the Tiananmen Gate. Two tourists were killed and 40 people were injured as the vehicle sped towards the entrance to the Forbidden City, just metres from the iconic portrait of Chairman Mao.

The occupants of the car — identified by the police as Usmen Hasan, his wife and his mother — died as it went up in flames. The police say that, in addition to petrol and a gas canister, investigators recovered from the vehicle two axes, metal clubs and a banner bearing “religious extremist messages”. The police did not disclose the content of the messages.

“This was a violent terrorist act that was carefully planned and organised,” the statement said.

The police said the five men were arrested 10 hours after the attack and had confessed their involvement. They said investigators had discovered long knives and a “jihadist” flag in the suspects’ temporary residence. It is unclear why the authorities delayed the announcement of the arrests by more than a day.

News of the arrests was played down in the Chinese media and most outlets carried only a brief statement from the official Xinhua news agency, reflecting in part the government’s skittishness over an incident that exposed security lapses at one of the nation’s most heavily-guarded locations.

According to The Wall Street Journal, Chinese Internet censors were busy deleting posts about the incident last night. More than 20 comments on the Chinese Wall Street Journal’s feed on the Twitter-like Sina Weibo account were moved in less than 10 minutes.

The attack is likely to prompt heightened security in Xinjiang, home to most of China’s ethnic Uighurs, a Turkic-speaking people who subscribe to a moderate brand of Sunni Islam. Uighurs have long had an uneasy co-existence with the ruling Han Chinese majority. But tensions have increased in recent years, fuelled by a surge in Han migration to the region, a widening income gap and anger over policies that many locals say marginalise Uighur culture and traditions.

The Chinese government often paints any resistance to its policies in Xinjiang as acts of separatism. But until the Tiananmen attack, most of the violence had been confined to Xinjiang, nearly 3,200km from Beijing.

Professor Rohan Gunaratna, an international terrorism expert at Nanyang Technological University in Singapore, said the attack would help bolster Beijing’s contention that Uighur Islamists have allied with a terrorist group known as the East Turkestan Islamist Movement and pose a serious threat to the nation. Although the authorities did not immediately link the attack to the group, Mr Gunaratna said he thought the episode would serve as a warning to those who have questioned its prowess.

As the authorities stepped up already-tight security in Xinjiang — several reporters there were turned back by the police at a roadblock outside Lukqun town, where one of the suspects was reportedly from — Mr Dilxat Raxit, a spokesman for the World Uyghur Congress, warned against believing China’s side of the story. He added that he was worried the incident would provide the authorities with an excuse “to further repress Uighurs”.

“If an attack is committed by a Han Chinese, it’s not terrorism, but if an Uighur commits it, it is,” Mr Raxit said. AGENCIES