The explosion took place this evening at the exit of the south railway station of Urumqi. Ambulances and police cars rushed to the scene, state-run Xinhua news agency reported.
People in the square in front of the station and nearby areas had been evacuated, it said, adding that police also evacuated people in surrounding areas.
Police have cordoned off all entrances to the square of the station. Armed police have been deployed in the square. Train services had been suspended at the station, it said.
Xi visited an armed police team in Kashgar, the border town close to Pakistan-occupied Kashmir, on Sunday where he acknowledged the complicated situation and the hardship the soldiers have endured.
Kashgar bore the brunt of attacks of Islamic militants as the security situation became tenuous with increasing tensions between Uygurs and Han settlers.
Thirty three people were killed 143 injured in knife attacks by a group of militants on passengers at Kunming Railway station on March 1.
