BALTIMORE — A Baltimore board has approved a six-month pilot program that will allow surveillance planes to patrol the city, a decision that drew opposition from civil liberties groups.

The Baltimore Sun reported the city’s Board of Estimates approved the contract on a 3-2 vote, giving the OK for a six-month pilot of the program.

It allows the planes to collect images of the city to help investigate murders, nonfatal shootings, armed robberies and carjackings.

Democratic City Council President Brandon Scott, who voted against the plan with Democratic City Comptroller Joan Pratt, questioned whether the technology was useful in solving homicides or robberies during an earlier trial.