Seven people were taken into custody early Tuesday after Chicago police said they vandalized "The Bean" in the city's Millennium Park and the Cancer Survivors' Wall in Maggie Daley Park.

Authorities said the group parked on Lower Wacker Drive and then spray-painted city property in the 300 block of East Randolph Street, where Maggie Daley Park is located, at around 11:58 p.m. Monday night. The group tagged several areas of the park, including the Cancer Survivors' Wall, police said.

Minutes later, at around 12:07 a.m., the group moved to Millennium Park where they tagged the iconic "Cloud Gate" sculpture known as "The Bean," as well as benches and other areas of the park. An off-duty security guard who was boarding a bus at the time spotted the group and alerted authorities, according to police, who took seven people, all described as adults, into custody.

Officers at the scene said the suspects arrested were "known taggers" who call themselves the "35th Street Crew." Several of the graffiti marks - including those on the "The Bean" - included "35th" in white spray paint, as well as the roman numerals for three and five, and the word "crew," among other symbols.

"Last night's vandalism to Chicago's iconic 'Cloud Gate' is reprehensible," the city's Department of Cultural Affairs and Special Events, tasked with handling the clean-up, said in a statement, adding, "Crews are in the process of removing the graffiti."

Charges were pending Tuesday against the seven people arrested in connection with the incident, according to Chicago police, who continue to investigate.

City officials said crews removed the graffiti with a "mild detergent to clean the surface and the area was polished with a stainless steel polish." The removal process took a couple of hours to complete.