A group of knife-wielding assailants burst into a train station in southern China late Saturday night and slashed to death at least 29 people and injured more than 100 others, according to state media.

The government-run Xinhua News Agency described the Kunming train station assault as a “premeditated violent terrorist attack” and identified the group of more than 10 assailants as Uighur separatists from China’s restive Xinjiang region. Authorities shot dead four of the assailants and arrested one, according to Xinhua.

Local news in Kunming, the capital city of Yunnan province, depicted gruesome scenes of victims sprawled on the train station floor splattered in blood.

A coordinated attack of this size and nature is rare in China. China’s leaders quickly responded with statements from top officials, and the country’s top security officials were en route to the scene.

The mass stabbing comes at a particularly sensitive time as top officials from China’s Communist Party are gathering for their most important public meeting on Wednesday, an annual convening of its largely rubber-stamp legislature in Beijing. In a sign of the incident’s sensitivity, many comments about the attack on Chinese social media were censored, and the news did not appear on the front pages of many newspapers.

China’s President Xi Jinping ordered “all-out efforts” to punish the attackers, “crack down on violent terrorist activities in all forms, safeguard social stability and guarantee the safety of people’s lives and property,” according to Xinhua.

Meng Jianzhu, head of China’s domestic security, and Guo Shengkun, minister of public security are on their way to Kunming, state media said.

Yang Haifei, a local resident, told state media the station transformed in an instant into a scene of panic and confusion, with everyone running away from the men in black. Yang said he was slashed in the chest and back. Those who were slower in getting out of the way were the most severely injured, he said, “They just fell on the ground.”

Xinhua quoted a 50-year-old farmer at the local hospital who said her husband was killed in the attack. Chen Guizhen said she and her husband had bought tickets for new jobs in a nearby city.

Xinhua described her holding an ID card covered in blood belonging to her husband and saying, “Why are the terrorists so cruel?”

The train attack comes on the heels of a spate of incidents that Chinese authorities have identified as acts of terrorism, including a jeep that crashed into Beijing’s Tiananmen Square in October. The jeep killed three who were inside and two pedestrians and injured at least 40 others. Authorities attributed the attack to men who appeared to be Muslim extremists, and a resulting increase in anti-terrorism security since then has focused on ethnic minorities, particularly Muslim Uighurs in the Western region of Xinjiang.

Many Uighur leaders have condemned the violence but also continued to report oppression by the official policies of China’s authoritarian government and by widespread discrimination within Chinese society.

Liu Liu in Beijing contributed to this report.