Twenty-nine people were killed and 130 were injured Saturday night when 10 men armed with long knives stormed the station in the southwest Chinese city of Kunming.

Members of a separatist group from Xinjiang, in northwest China, are believed to have carried out the assault, CNN said. The report referred to them as "terrorists."

Police said they killed at least four attackers and shot and wounded a female suspect. Authorities were searching for other suspects, said CNN.

China’s President Xi Jinping ordered a crackdown on “violent terrorist activities” after evidence at the scene showed it was a terrorist attack orchestrated by Xinjiang separatist forces, the state-run Xinhua News Agency reported. A group promoting human rights for the region’s minority people, the Uighur, called for a transparent investigation.

Violent terrorist attacks have been increasing since 2009 and have become the biggest security threat to Xinjiang, Xinhua said. Some 190 terrorist attacks were recorded in the region in 2012, increasing by “a significant margin from 2011,” it said, citing the regional public security bureau.