( CNN ) -- 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 . CNN 's Pierre Meilhan and Euan McKirdy contributed to this report .
NEW : President Xi -- who was visiting region -- urges `` decisive actions '' against terror attacks . NEW : Station reopens 2 hours after blast , as passengers return as armed police watched . Posted at 12:29 PM ET on Jun 25, 2015 | There have been tensions between Uyghurs and Han Chinese in Xinjiang .