A duffel bag containing human remains was found outside a biotechnology building in Cambridge on Saturday morning, and one person was later arrested in connection with the grisly discovery, authorities said.

The duffel bag was found shortly before 8 a.m. near a building used by biotechnology company Biogen Inc. and a block from a police station, Middlesex District Attorney Marian T. Ryan said. Video surveillance of the area led police to an apartment building across the street where additional human remains were found in a common area, authorities said.

All of the remains are believed to belong to one person, whose death is being treated as a homicide, Ryan said. She announced at an evening news conference that a suspect had been arrested in the case but provided no details. The name of the victim also was not released pending notification of next of kin.

Ryan said the suspect would be arraigned Monday in Cambridge District Court on charges of being an accessory after the fact to assault and battery causing serious bodily injury and improper disposal of human remains. The defendant's name was not being released ahead of the arraignment.

"We're confident that this was not a random act and there is no threat to the public's safety as a suspect has been taken into custody," Cambridge Police Commissioner Robert Haas said in a statement.

The neighborhood where the duffel bag was found includes Kendall Square near the Massachusetts Institute of Technology and Harvard Square.

The Biogen building was cordoned off with caution tape Saturday morning as investigators examined the bag. A spokesman for Biogen referred all inquiries to police.

The chief assured residents of the apartment building that they were safe and said officers would remain there for the rest of the evening. Residents who left the building were allowed to re-enter only after showing proof they lived there; officers would then escort them to their apartments.