Chinese police said Monday three suspects involved in the terrorist attack in the southwestern city of Kunming had been captured.

The Ministry of Public Security said in a statement that the terrorist gang led by Abdurehim Kurban was responsible for the attack.

Police shot and killed four of them and captured an injured female attacker at the scene on Saturday night, the statement said.

The knife-wielding attackers slashed frantically at crowds at a railway station in Kunming in southwest China's Yunnan province on Saturday, killing 29 people and injuring 143.

The health authority said 20 of the 143 injured in Kunming are still in critical condition.

Soon after the terrorist attack, Chinese President Xi Jinping ordered law enforcement agencies to strike out with full forces and bring those accountable to justice as soon as possible.

Xi urged the greatest efforts to treat the injured and help those who have lost their loved ones.

Chinese Premier Li Keqiang ordered police forces nationwide to beef up security, particulary at public places of big crowds.

Senior Chinese security official Meng Jianzhu arrived in Kunming at 5:30 a.m. Sunday to oversee the situation.

Order was restored in Kunming on Sunday, with train arrivals resumed after three trains with 3,000 passengers were affected on Saturday night. About 60,000 passengers left the station on Sunday, higher than the 59,000 on Saturday. All local middle and primary schools opened as normal on Monday, with enhanced security.

Chinese leaders and political advisors Monday paid silent tribute to the victims of the terrorist attack at the opening of the annual session of the National Committee of the Chinese People's Political Consultative Conference (CPPCC).

Du Qinglin, vice chairman of the CPPCC National Committee, condemned the terrorists behind the attack and conveyed condolences to the victims.

"The violent terrorist attack in Kunming on March 1 has caused great losses to people's lives and property," said Du.

The carnage has shocked and outraged the international community. United Nations Secretary General Ban Ki-moon condemned the terror attack.

"Terrorist attacks cannot be justified under any circumstances and under any reasons," stressed Ban. "This was unacceptable. The perpetrators must be brought to justice."

Ban conveyed his "most sincere condolences and sympathies to those families of the victims" and wished those injured a speedy recovery.

"The international community has suffered too much, [and] too long by these terrorist attacks here and there. We must be united to fight against terrorism," Ban said.

Germany strongly condemned the mass stabbing at the train station soon after the bloody attack.

"We condemn the brutal attack on innocent civilians at a train station in Kunming in southwest China in the strongest terms," a German foreign ministry spokesman said in a statement. "This act cannot be justified."

Other countries, including France, Russia, the United States, Britain, Australia, and Afghanistan, all expressed condemnation of the brutal violence that caused heavy casualties.

Flags of 'East Turkistan' forces found at Kunming station

Police have found flags of "East Turkistan" forces at a Chinese train station where a terrorist attack killed at least 29 civilians and injured over 140 in the southwestern city of Kunming, a spokesman said on Monday.

"Some flags of the 'East Turkistan' forces were discovered at the site, according to the initial findings of the police. Investigation of the terrorist attack is still under way," Foreign Ministry spokesman Qin Gang said at a daily news briefing.