- President Xi -- who was visiting region -- urges "decisive actions" against terror attacks
- Station reopens 2 hours after blast, as passengers return as armed police watched
- The explosion happened at an exit to a train station in Urumqi in China's restive northwest
- There have been tensions between Uyghurs and Han Chinese in Xinjiang
Three people died and 79 others were injured, four seriously, in a suspected terror attack Wednesday in China's restive northwestern region.
The incident spurred the nation's President Xi Jinping -- who was completing a four-day tour to the area -- to vow action against separatist attacks, state news reported.
An explosion rocked the South Railway Station of Urumqi, capital of China's Xinjiang Uyghur Autonomous Region, followed by a knife attack at the same location.
Xinhua announced the casualty toll via Twitter early Thursday, as well as Xi's urging "decisive actions" in response.
"The battle to combat violence and terrorism will not allow even a moment of slackness, and decisive actions must be taken to resolutely suppress the terrorists' rampant momentum," state-owned media reported Xi as saying.
Xinhua, quoting police, also said "knife-wielding mobs" attacked people at one of the station's exits following the blast, which occurred around 7 p.m. Wednesday.
Police evacuated people from the square in front of the station, deployed armed officers and cordoned off entrances to the station, where train services had been suspended.
The station reopened about two hours later. with passengers re-entering under a heavily-armed police presence.
Frequent outbreaks of violence have beset Xinjiang, a resource-rich region where the arrival of waves of Han Chinese people over the decades has fueled sectarian tensions with the Uyghurs, a Turkic-speaking, predominantly Muslim ethnic group.
China was shocked in March as a violent terror attack in another train station, in Kunming, saw 10 men armed with long knives kill 29 commuters.
The fight against separatist violence in the autonomous region was a focus of the Chinese leader's visit.
During his tour, Xi visited security forces and watched an anti-terror drill, Hong Kong's South China Morning Post reported.
"The battle to combat violence and terrorism will not allow even a moment of slackness, and decisive actions must be taken to resolutely suppress the terrorists' rampant momentum," Xinhua quoted Xi as saying during his tour.
He also stressed the importance of "long-term stability" in the region as "vital to the whole country's reform, development and stability; to the country's unity, ethnic harmony and national security as well as to the great revival of Chinese nation."
Speaking to local officials, the President called for national unity and opposition to separatism. He said China will use a "strike-first" strategy against militants in the region and forge policies to promote ethnic harmony.