Three people were killed and 79 injured in an attack Wednesday night on a train station at the tail end of Chinese President Xi Jinping’s visit to the restive province of Xinjiang, according to state media.

State-run media described an explosion and a group of knife-wielding attackers slashing at people at the exit of the South Rail Station in the Xinjiang capital of Urumqi.

The attack appeared timed to Xi’s first visit as president to Xinjiang — a four-day tour that ended Wednesday of an area where Muslim minorities have often clashed with Chinese authorities in violent confrontations. It was not clear whether Xi was still in the province at the time of the attack.

Chinese authorities said Thursday that the attack was carried out by two religious extremists, who detonated explosives in an apparent suicide bombing that killed both of them and one other person, the Associated Press reported.

The bombing, which state news media called a terrorist attack, comes on the heels of increasingly brazen strikes attributed to Muslim extremists and separatists.

Armed police officers stand guard at the South Railway Station, where three people were killed and 79 wounded in a bomb and knife attack, in Urumqi, in this still image taken from CCTV video shot April 30, 2014. The incident occurred in the far western region of China. (Handout/Reuters)

On Thursday morning, Xi promised “decisive action” on the train attack, according to state-run Xinhua News Agency, and urged authorities to find those behind it.

Communist Party leaders have shown increasing concerned about Muslim extremists in Xinjiang. Last Friday, Xi was quoted in state media calling for intensifying counterterrorism measures.

Chinese must “make terrorists become like rats scurrying across a street, with everybody shouting ‘beat them!’” Xi was quoted as saying by Xinhua.

Some photos showing the aftermath of the attack, circulated late Wednesday night on the Chinese equivalent of Twitter called Weibo, but were quickly censored. According to Freeweibo, a group that follows censored postings, even the account of state-run Xinhua was censored overnight with posts carrying President Xi’s response deleted.

The train attack is the latest in a spate of incidents that Chinese authorities have identified as acts by Muslim terrorists, including an attack by knife-wielding assailants on another train station in southern China in March that killed 33 people and injured more than 100 others.

In October, a Jeep that crashed into Beijing’s Tiananmen Square killed three who were inside and two pedestrians and injured at least 40 others.

Authorities attributed both attacks to Muslim extremists from Xinjiang, and a resulting increase in anti-terrorism security since then has focused on Uighur ethnic minorities in the region.

Uighur groups expressed concern the latest attack could result in increased crackdown on minorities. “More than 100 Uyhurs have already been arrested because of the blast,” according to Dilshat Rexit, spokesperson for the World Uyghur Congress. “Uyghurs who are struggling from despair and survival hope Xi Jinping can bring constructive and specific advice to improve the turbulent situation. However, on the contrary, Beijing continues to encourage violent suppression on Uyghurs,” he said in an e-mail.

For years, many Uighurs and other smaller Muslim minorities in Xinjiang have long agitated against China’s authoritarian government. Their protests are a reaction, Uighur groups say, to oppressive official policies, religious restrictions and widespread discrimination.

The Chinese government has long denied any oppression of Uighurs or any other ethnic group.

Ethnic rioting and clashes in Xinjiang reached a peak in 2009, causing roughly 200 deaths and triggering a crackdown by local authorities. Renewed protests last year also turned violent and are thought to have claimed more than 100 lives.

In a statement in Xinhua Thursday morning, President Xi vowed that “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.”

Meanwhile, Rexit from the World Uyghur Congress said, “The blast in Urumqi once again proved that forceful suppression [of minorities] cannot solve the problem. . . . Any provocation by China will further exacerbate and directly stimulate the turbulent situation.”

Liu Liu and Xu Jing contributed to this report.