Security has been ramped up in Kunming, south-west China, after a horrific mass knife attack left 29 people dead and more than 130 people injured. There are reports of a heavy police presence at the Kunming train station, the site of Saturday’s attack, and in surrounding areas, according to the BBC.

Kunming’s Changshui International Airport saw increased security checks today, and police presence in Beijing is also reportedly higher. On Sunday night, more than 100 people attended a vigil at the Kunming train station to mourn the victims of the attack.

A group of men and women, clad in black and wearing cloth masks, entered the Kunming train station on Saturday, wielding knives, meat cleavers, and swords and randomly stabbed passengers and employees. There were at least 10 suspected attackers, and four were shot dead at the scene.

Chen Bing, a resident of Kunming, told the South China Morning Post: "I hate those terrorists. I want to in any way I can express my feelings of grief for those killed and injured."

Chinese officials blamed Uighur separatists from the country’s Xinjiang region for the attack on Sunday. Uighurs, a Muslim minority group living in far-west China, often shoulder the blame for violence by Chinese authorities, who are known for exaggerating the threat of Islamic terrorism they pose. 

Another man, who didn’t want to be named, told the South China Morning Post that he was concerned with unrest in Xinjiang. “We were never told why there was so much unrest there… what did our government do there to attract that much anger?” he said.

While no group has yet come forward to claim responsibility for the attack, it is hard to verify China’s reports that Uighur extremists are to blame because access to the region for foreign journalists is notoriously restricted. Beijing is expected to say that train station attack demonstrates that the Uighur threat is real.

The United Nations has condemned the attack, with UN Secretary-General Ban Ki-moon calling the attack “terrible.”

“There is no justification for the killing of innocent civilians,” he said.