CHICAGO — A massive manhunt is underway for two bank robbers who pulled off a daring escape from downtown Chicago’s high-rise jail Tuesday by apparently squeezing through a narrow window and scaling down about 20 stories using a makeshift rope.

The two men were first unaccounted for during a 5 a.m. head count, but it is unclear if they were still inside the 27-story Metropolitan Correctional Center at the time, US Marshal’s Service spokeswoman Belkis Cantor said.