Beijing police said Friday they held an "anti-terror" drill at a rail station, a day after a deadly bombing in China's far west blamed on alleged attackers infused with "religious extremism".

The drill, involving armed officers, began late Thursday at Beijing Railway Station, police said on their official account on Sina Weibo, a Chinese equivalent of Twitter.

The drill underscores official concerns about terrorism following an apparent suicide bomb attack Wednesday at a railway station in the restive region of Xinjiang that left three dead, as well as 79 people wounded.

Two of the dead had detonated bombs they were carrying, state media said, adding that the other fatality was an "innocent citizen".

The official Xinhua news agency called it a "violent terrorist attack", and said the suspects had "long been involved in religious extremism".

Xinjiang is home to the mostly Muslim Uighur ethnic minority, who are sometimes implicated in clashes with local security forces.

China's government blamed "separatists," from Xinjiang for a March knife attack at a railway station in the southern city of Kunming in which rampaging attackers killed 29 people and wounded 143 in what state-run media dubbed the country's "9/11".

The Beijing police statement made no mention of the violence in Xinjiang, but said that the drill was meant to simulate a "violent terror incident" at Beijing Railway Station.

The exercise began at 11:50 pm Thursday and ended at 12:25 am Friday, the statement said, adding that police as well as SWAT and anti-terror personnel participated.

Wednesday's violence in Xinjiang came the same day that state media said Chinese President Xi Jinping wrapped up an "inspection tour" to the region.

Xinjiang is a vast, resource-rich and nominally autonomous region, where decades of migration by China's dominant Han majority has fostered tensions with Xinjiang's Uighurs.

During Xi's trip, his first to Xinjiang since becoming head of China's ruling Communist Party in November 2012, he visited military facilities, conferred with police personnel and spoke to primary school students.

Even before Wednesday's violence, Xi was quoted by state media as telling law enforcement personnel in Xinjiang that they must "have effective methods to handle violent and terrorist criminals".

After the attack, he said "decisive actions must be taken to resolutely suppress the terrorists' rampant momentum".

China announced in March that it plans to roll out armed police patrols in cities across the country following the attack in Kunming.