Kyiv Mayor Vitaly Klitschko on Thursday announced an overnight curfew in Ukraine's capital as the country battled to repel a Russian invasion.

The former world heavyweight boxing champion said the curfew would last from 10:00 pm to 7:00 am local time (2000-0500 GMT) and that public transport would stop working during that period.

Metro stations would remain open throughout to serve as bomb shelters, he said. 

Meanwhile, in a message posted on his official Telegram channel, he said an "operational headquarters has been set up to coordinate the actions of the executive branch, the military command and law enforcement agencies." 

Klitschko said the measures would also include "strengthening the protection of public order and facilities that ensure the life of the city" as well as the prohibition of mass events and protests, and of the "production and distribution of information materials that may destabilize the situation."

Military "conscripts and reservists are prohibited from changing their place of residence without notifying the relevant authorities," the message also said.

(With input from agencies)