SOUTH PORTLAND, Maine — South Portland police were executing a "high-risk warrant" late Friday afternoon on Main Street, dispatch said.
The heavy presence was concentrated at 757 Main St. at Kings Wood Park apartment complex, the address at which the warrant was being served.
Police said a suspect inside was barricaded.
The warrant was served, according to an official, but the suspect went back inside where police had reason to believe there were volatile chemicals.
Two other people had been detained, officials said.
Main Street was open as of 5:45 p.m., but the heavy law enforcement presence remained.
Police said residents of 757 Main St. were being evacuated to 751 Main St.
An officer said the process could take a couple hours.