China has ordered stepped-up safety measures over the Lunar New Year travel rush in the wake of terrorist threats and a December stampede in Shanghai that killed 36 people.

The government estimates about 2.8 billion trips will be made by train, bus, plane and car during the 40-day travel rush that began in early February and ends around March 15.

While the travel peak is always hectic, special measures have been put in place this year, including the posting of more armed security guards, restricted access to crowded areas such as train platforms and the stationing of watchmen on elevated posts to keep an eye out for trouble.

A circular from China's Cabinet posted Saturday demanded greater attention to safety and threatened punishment for officials found lacking in their duties.

Shanghai fired four top officials and disciplined seven others over the Dec. 31 stampede in the city's historic riverfront Bund area, saying some of the officials were attending an opulent banquet as the disaster unfolded.

An investigation blamed the officials for failing to take proper precautions at the scene and for not responding fast enough to the disaster — the worst to hit China's showcase financial center in recent years.

Authorities are also on guard against attacks blamed on ethnic Uighur extremists seeking independence for the northwestern region of Xinjiang. Rumors have circulated online about plots being planned against transportation sites, similar to the March 29, 2014, attack on a train station in the southwestern city of Kunming in which 31 people were slashed and stabbed to death.

Beijing says that and other attacks were carried out by radicals inspired by extremist Islamist teachings.