Witnesses of a horrifying attack at a Chinese train station which killed 29 people and wounded more than 130 described Sunday how injured victims fled in panic amid the sound of gunshots.

A heavy police presence was in place at Kunming station in the southwestern province of Yunnan after knife-wielding attackers slashed indiscriminately as people queued to buy tickets late Saturday, an incident blamed by authorities on separatists from the restive Xinjiang region.

A station cleaner, who gave his surname as He, said police fired on the assailants for about half an hour as scores of people were being carried out on stretchers with bandaged wounds.

State media said at least four attackers were shot dead, while one was arrested. The hunt for others continues.

"I saw five of them leaving... Then I heard gunshots. (It was) likely to be going on for half an hour," said He, adding he felt terrified returning to work the morning after the bloodshed.

Recalling the horror felt by people at the station the previous night, the cleaner said: "I felt frightened, everyone ran out. The streets were blocked (by police).

"I saw five people holding knives, walking slowly down there to the bus station," he added, pointing in the distance at the busy intersection that fronts the main rail terminal for Yunnan province.

The 49-year-old said he saw some of the 130 people who were said by authorities to have been wounded in the attack being taken away on mobile stretchers, their heads "wrapped in bandages".

"I saw adults, no kids," he said, adding: "The ambulances must have been too busy, as the buses and taxis were being used."

A shop worker nearby told AFP some of the victims took refuge in her store.

"Many were crying and some looked like they had been cut. We were terrified," she said, pointing to a space behind a row of instant noodles where the panic-stricken victims had sought shelter.

"Everyone in Kunming is still in shock."

Parts of the sprawling train station were still cordoned off by police on Sunday afternoon, as locals took pictures of the scene with their phones, many shaking their heads.

Armed police stood behind tape which closed off the temporary waiting area -- which AFP was told witnessed the first scenes of carnage -- at the front of the station.

Further inside the station, where the attackers were said to have fanned out as they continued their frenzied assault, long queues of commuters waited patiently at the main ticket hall.

It was far removed from the chilling violence witnessed the night before, in what state media have called "China's 9/11".

"I can't believe this has happened in my city," said one commuter, looking around at hundreds of people in the hall, all wearing identical stunned expressions.

"But we have to continue with our lives, or the attackers would have won."

Timeline of unrest related to China's Xinjiang region
Beijing (AFP) March 02, 2014 - At least 29 people have been killed and more than 130 wounded in a mass stabbing attack at a Chinese train station, with authorities blaming separatists from Xinjiang, home to the mainly Muslim Uighur minority.

Here is a chronology of key events related to the restive region since 2009:

2009

June 25 -- Two Uighur factory workers are reported killed and dozens injured in a huge brawl with Han Chinese in Shaoguan, in the southern province of Guangdong.

July 5 -- Hundreds, perhaps thousands, of Uighurs riot in the Xinjiang capital Urumqi after security forces move in on a protest over the Shaoguan incident.

July 7 -- The government says nearly 200 people died in the unrest, with more than 1,600 injured and hundreds arrested. Eventually at least 26 are reportedly sentenced to death.

September 2 -- Han residents of Urumqi protest for days over a wave of syringe stabbings which the government eventually says had nearly 500 victims, blaming "ethnic separatist forces".

2011

July 18 -- Police kill 20 protesters in clashes in Hotan, southern Xinjiang, exiled Uighur groups say. State media say police fired on demonstrators who attacked a police station, killing one officer.

July 31-August 1 -- Two attacks by alleged terrorists leave 13 people dead in a Han Chinese section of Kashgar, while police kill eight suspected Uighur separatists.

September 15 -- Courts in Xinjiang sentence to death four Uighurs over the July incidents.

December 28 -- Police in Pishan kill seven "terrorists" in a hostage standoff that left one officer dead. State media calls them terrorists engaged in a "holy war".

2012

February 28 -- Rioters armed with knives kill at least 10 people in Yecheng, while police shoot two of the attackers dead, state press say. One man is later sentenced to death.

2013

April 23 -- Gunfights in Bachu leave 15 police and community workers and six "terrorists" dead. Two men are later sentenced to death.

June 26 -- At least 35 people are killed when, according to Xinhua, "knife-wielding mobs" attack police stations and other sites in Lukqun before security personnel open fire. Three people are later sentenced to death.

August 20 -- A Chinese policeman is killed in what state media call an "anti-terrorism" operation in Yilkiqi. Overseas media report 22 Uighurs were shot dead.

October 28 -- Three members of the same Xinjiang family crash their car into tourists in Tiananmen Square in Beijing, the symbolic heart of the Chinese state, killing two, before setting it on fire and dying themselves, according to authorities who call it a terrorist attack.

November 17 -- Two policemen and nine attackers are killed at a police station in Serikbuya, state media say. Rights groups say the trigger was the fatal shooting of a Uighur youth during a protest.

December 16 -- 14 Uighurs and two police officers are killed in Shufu county. Authorities describe the slain Uighurs as members of an extremist group, but campaigners say police raided a house where a family was preparing for a wedding, with six women among those killed.

December 30 -- An assault on a police station in Yarkand leaves eight attackers dead, according to the Xinjiang government's official website.

2014

January 15 -- A prominent Uighur academic and critic of government policy, economics lecturer Ilham Tohti, is detained by police, his wife says, and later charged with separatism, which can carry the death penalty.

January 25 -- A total of 12 people have been killed in Xinhe, six in explosions and six shot dead by police dealing with "violent incidents", a government-run news portal says.

February 14 -- A total of 11 people die in an attack on police in Wushi, with officers shooting eight dead and three blowing themselves up, authorities say.

March 1 -- At least 29 people are killed and more than 130 wounded by knife-wielding assailants at Kunming train station in Yunnan province, more than 1,600 kilometres (1,000 miles) from Xinjiang. Officials blame separatist terrorists from Xinjiang.