Detectives in Durham City are investigating two incidents in which a man demanded cash.
It is understood the first incident occurred on Claypath at around 6.49pm on Wednesday, October 11, where a man approached a member of the public and demanded money. He then assaulted the individual and made off without cash.
The second incident happened on the steps leading to the city from the train station at around 8:50pm on Wednesday. On this occasion a man is believed to have been demanding money from members of the public while making threats.
Officers are keen to speak to anyone who may have witnessed the incidents.
Detective Sergeant Chris Woollett, from Durham Constabulary, said: "Both of these incidents occurred in the city where lots of people will have been around. I would urge anyone with any information to come forward."
Contact police with any information on 101, quoting incident number 421 of October 11
Alternatively information can be passed to Crimestoppers anonymously on 0800 555 111.