Update: The standoff concluded Monday morning with the discovery of two bodies. Read KTLA's new article.
Seal Beach police and SWAT officers responded to a possibly armed man who may have barricaded himself inside an apartment complex on Sunday night.
Authorities were called to the scene around 7:20 p.m. after receiving a call from a woman requesting help at a residence near the intersection of 7th Street and Central Avenue.
The line was disconnected and witnesses reported hearing several gunshots, according to Sgt. Michael Henderson with the Seal Beach Police Department.
Officers surrounded the building and nearby homes were evacuated, according to the the Department.
Witnesses at the scene told KTLA that the suspect may be an off-duty police officer but authorities have not yet confirmed his occupation.
Authorities would not release further information due to the ongoing tactical situation, Henderson added.