Two men allegedly used a loudspeaker to proclaim the end of the world on the city's streets on Sunday while another two allegedly distributed related pamphlets.
They were given 10 days of administrative detention, state-run Xinhua news agency reported quoting local officials.
Rumours stating that the world will end on December 21, 2012 are popular in China, despite having debunked multiple times.
The rumour is related to myths stating that a calendar used by the ancient Maya accurately predicts the end of the world.
Police said local residents should abide by the law and refrain from spreading doomsday rumours.
Punishments will be given to those who disseminate rumours in order to cause trouble, defraud others or disturb social order, the statement said.