CHICAGO (WLS) -- Surveillance video shows one of four offenders wanted in several robberies, some of which involved a gun, on the city's North Side.Authorities said the string of robberies in neighborhoods across the North Side could be linked. All included multiple offenders in a black SUV, which police said they recovered after a brief pursuit. It was left abandoned on the city's South Side.Now police are looking for the offenders.Over the weekend, pizza delivery driver Alegundo Sanchez was robbed outside his restaurant. The security camera captured images of the robbery and of the one offender."I opened the door, and they got out of another car, pulled a gun, and said, 'Give me the wallet,'" Sanchez said.Sanchez was a victim in one of more than a dozen robberies in the last week on the city's North Side. Just Monday night, the robbers struck several times. At Broadway and Wellington, they got away with a wallet after pistol-whipping the victim, police said.Four other robberies occurred within hours of each other on Christmas Eve and Christmas Day.On December 24, 2015, at 1:50 a.m. in the 400 block of West Wrightwood, a man was robbed by two men who got out of a black SUV. The victim said the offenders searched him and took his cell phone before fleeing.Seven minutes later in the 1600 block of West Berwyn, two men were approached by an offender as one of them urinated in an alley. They were both beaten up and robbed.Hours later, at 10:50 p.m., a man was walking in alley in the 1000 block of W Newport when a few men in a black SUV surrounded him. One of the offenders pulled a handgun and told him to "empty your pockets," police said. He was not injured.At 1 a.m. on December 25, 2015, in the 2100 block of West Wellington, a woman was approached from behind by an offender and knocked on the head with an ornamental candy cane. He fled with her bag, police said.Earlier robberies involving multiple offenders occurred:- 3900 block of North Spaulding Ave. on 22 December 2015- 5300 block of North Kedzie Ave. on 22 December 2015- 5100 block of North Avers Ave. on 22 December 2015- 6800 block of North Seeley Ave. on 23 December 2015- 4800 block of North Seeley Ave. on 23 December 2015- 5400 block of North Kedzie Ave. on 23 December 2015- 3800 block of West Belle Plaine Ave. 23 December 2015- 3600 block of West Berteau Ave. 23 December 2015The offenders are described as black males with light to medium complexions who are between the age of18 and 24 years old, 5'6" to 5'11" tall, and weigh 40 to 170 pounds.Anyone with information should call Area North Detectives at 312 744-8263.