An attack at a train station in the far western Chinese city of Urumqi was carried out by two religious extremists, who both died in the attack, the regional government said on Thursday.
The Xinjiang government said on its official news website that the two had "long been influenced by extremist religious thought and participated in extremist religious activities".
This comes after the state media said that two of the assailants who carried out a bombing in western China were among the three people killed, in an attack which also wounded 79 and has raised concerns over its apparent sophistication and daring.
The People's Daily, the official newspaper of the ruling Chinese Communist Party, said on its official microblog that "two mobsters set off bombs on their bodies and died", though the report did not call it a suicide bombing.
The other person who died was a bystander, the People's Daily said.
Knives and explosives were used in the assault on a railway station in Urumqi on Wednesday, the first bomb attack in the capital of Xinjiang region in 17 years. The attack was carried out soon after the arrival of a train from a mainly Han Chinese province, state media said.
The bombing was possibly timed to coincide with a visit to the region with a large Muslim minority by President Xi Jinping, when security was likely to have been heavy.
On Thursday, dozens of black police vans were parked around the station, while camouflaged police with assault rifles patrolled its entrance. Despite the security, the station was bustling and appeared to be operating normally.
The government blamed the attack on "terrorists", a term it uses to describe Islamist militants and separatists in Xinjiang who have waged a sometimes violent campaign for an independent East Turkestan state - a campaign that has stirred fears that jihadist groups could become active in western China.
State media accounts did not say if any other attackers had been killed or captured. Nor did they say if Xi, who was wrapping up his visit, was anywhere near Urumqi at the time.
Pan Zhiping, a retired expert on Central Asia at Xinjiang's Academy of Social Science, described the attack as very well organised, saying it was timed to coincide with Xi's visit.
"It is very clear that they are challenging the Chinese government," he said.
"There was a time last year when they were targeting the public security bureau, the police stations and the troops. Now it's indiscriminate - terrorist activities are conducted in places where people gather the most."
There has been no claim of responsibility for the attack.
But the language used by the government to describe the incident, with the reference to the assailants as "terrorists", implies that it was carried out by Uighurs, the Muslim people who call Xinjiang home, many of whom chafe at government controls on their culture and religion.
In remarks released on Thursday from Xi's trip to Xinjiang this week, the president urged troops based in the region to "strike crushing blows against violent terrorist forces and resolutely strike against terrorists who are swollen with arrogance".
"Resolutely crush the space for terrorist activities and contain the spreading trend of escalation," Xi said, in comments carried by the official Xinhua news agency.
REUTERS