Extra police officers were drafted into East Hull after armed robbers raided a service station and a cyclist was also attacked.
The incidents began when two men entered the BP service station on Leads Road shortly after 11pm on Saturday April 22 and threatened the staff with two weapons.
The men then stole cash and cigarettes and left the scene. The staff were not physically harmed but were shaken by the incident.
A further incident occurred a few minutes later on a cycle path between Chamberlain Road and Ashendon Drive where a man was threatened by two men with weapons who stole his mobile phone (a white and gold IPhone 5S with black case) and his cycle. The man was grabbed and taken to the ground but not injured in the incident.
The two men are described as both being white, around 5ft 6/8 inches tall, of medium build and in their mid-20s. They spoke with local accents and were both dressed in black.
In a statement Humberside Police spokesman said: “We would reassure residents that we are doing all we can to investigate both of these incidents and do not want to cause alarm, but are urging residents in the area to be extra vigilant while these individuals are still at large. We are providing extra police officers in the area this evening and would ask if anyone sees anything suspicious to call 999.
“We are appealing for anyone who witnessed either incident, who has not already spoken to the police, to contact us on 101 quoting log 696 22/04/2017. They can also call Crimestoppers anonymously on 0800 555111.”