China's official Xinhua News Agency did not identify who might have been responsible for the late-evening attack at the Kunming Railway Station in Yunnan province, but said authorities considered it to be "an organized, premeditated violent terrorist attack."

In an indication of how seriously authorities viewed the attack, one of China's deadliest in recent years, the country's top police official, Politburo member Meng Jianzhu, was on route to Kunming, the Communist Party-run People's Daily reported.

The violence in Kunming came at a sensitive time as political leaders in Beijing prepared for Wednesday's opening of the annual meeting of the nominal legislature where the government of President Xi Jinping will deliver its first one-year work report.