Beijing — More than 10 knife-wielding attackers slashed people at a train station in a southwestern city in what authorities called a terrorist attack by ethnic separatists in western China, and police fatally shot four of the assailants, leaving 33 people dead and 130 others wounded, state media said.

The attackers, most of them dressed in black, stormed the Kunming train station in Yunnan province and started attacking people Saturday evening, according to witnesses.

Student Qiao Yunao was waiting to catch a train at the station when people starting crying and running, and then saw a man slash another man's neck, drawing blood.

"I was freaking out, and ran to a fast food store, and many people were running in there to take refuge," she told The Associated Press via Sina Weibo, a Chinese microblog. "I saw two attackers, both men, one with a watermelon knife and the other with a fruit knife. They were running and chopping whoever they could."

Another witness, Yang Haifei, said he saw a person "come straight at me with a long knife and I ran away with everyone." People who were slow to escape ended up severely injured, he told the official Xinhua News Agency. "They just fell on the ground," Yang said from a hospital where he was being treated for chest and back wounds.

One suspect was arrested, Xinhua said. Evidence found at the scene of the attack showed that it was "a terrorist attack carried out by Xinjiang separatist forces," the agency quoted the municipal government as saying. Authorities considered it to be "an organized, premeditated violent terrorist attack."

The far western region of Xinjiang is home to a simmering rebellion against Chinese rule by separatists among parts of the Muslim Uighur (pronounced WEE'-gur) population.

Most attacks blamed on Uighur separatists take place in Xinjiang, but Saturday's assault took place more than 620 miles to the southeast in Yunnan, which has not had a history of such unrest. However, a suicide car attack blamed on Uighur separatists that killed five people at Beijing's Tiananmen Gate last November raised alarms that militants may be aiming to strike at targets throughout the country.

In an indication of how seriously authorities viewed the attack — one of China's deadliest in recent years — the country's top police official, Politburo member Meng Jianzhu, arrived in Kunming this morning and went straight to the hospital to visit the wounded and their families, Xinhua reported.

The violence in Kunming came at a sensitive time as political leaders in Beijing prepared for Wednesday's opening of the annual meeting of the nominal legislature where the government of President Xi Jinping will deliver its first one-year work report.

Xi called for "'all-out efforts" to bring the culprits to justice. In a statement, the Security Management Bureau under the Ministry of Public Security said that police will "crack down the crimes in accordance with the law without any tolerance."

A Xinhua reporter on the scene in Kunming said several suspects had been "controlled" while police continued their investigation of people at the train station. The reporter said firefighters and emergency medical personnel were at the station and rushing injured people to hospitals for treatment.

More than 60 victims of Saturday's attack were taken to Kunming No. 1 People's Hospital, where at least a dozen bodies also could be seen, according to Xinhua reporters at the hospital.

At a guard pavilion in front of the train station, three victims were crying. One of them, Yang Ziqing, told Xinhua that they were waiting for a train to Shanghai when a knife-wielding man suddenly came at them.

"My two town-fellows' husbands have been rushed to hospital, but I can't find my husband, and his phone went unanswered," Yang sobbed.

Xinhua said some victims were migrant workers who were returning to factories after family reunions over the Chinese New Year.

Footage on China's state broadcaster CCTV showed a heavy police presence near the station and plainclothes agents wrapping a long knife in a plastic bag as investigators collected evidence following the attacks.

Pictures on Sina Weibo, the Chinese equivalent of Twitter, showed bodies covered in blood at the station.

The Kunming railway station, located in the southeastern area of the city, is one of the largest in southwest China.

Associated Press researcher Fu Ting in Shanghai contributed to this report.