China's top legislators and political advisors have expressed their support for an iron-fist crackdown on terrorism after a bloody killing spree by Xinjiang separatists left 29 civilians dead in the country late Saturday.

"We should launch a nationwide campaign against such terrorist activities and resolutely fight the terrorists," said Yin Zhuo, director of the Expert Consultation Committee of the People's Liberation Army (PLA) Navy.

"The well-planned attack was not an issue of ethnics or religion, it was an issue of terrorism with links to the terrorist forces out of the country," said Yin, who is also a member of the National Committee of the Chinese People's Political Consultative Conference (CPPCC).

His remarks came hours after knife-wielding separatists from Xinjiang killed 29 and injured over 130 in a train terminal in Southwest China's Kunming City.

Chen Shu, a deputy to the National People Congress (NPC), the country's top legislature, urged a "quick and harsh crackdown on the terrorist activists."

"The attack against innocent civilians was a crime against the humanity," said Chen, who is also the honorary chairman of the Lawyers' Association of Guangzhou City in South China's Guangdong Province. "All countries should join hands to fight terrorist activities like this one."

The NPC and CPPCC National Committee annual sessions are scheduled to open this week in Beijing, where the country's lawmakers and political advisors are convening.