Updated

A Florida man remained barricaded in an Orlando apartment complex Monday afternoon more than 12 hours after he shot a police officer and took four children hostage, police said.

The Orlando police officer, who was not identified, was responding to a domestic violence call at the Westbrook Apartments near Universal Studios around 11:45 p.m. Sunday when the suspect opened fire. The officer was taken to the hospital and underwent surgery.

“It is a very serious, significant injury,” Orlando Police Chief John Mina said at a news conference Monday. “He is expected to survive."

The suspect barricaded himself inside the apartment and took four children — ages 1, 7, 10 and 12 — as hostages, Mina said. He added that the children may have been the suspect's children.

SWAT was at the scene negotiating with the suspect early Monday morning.

“Our main concern right now is the safety of the children in that apartment,” the police chief told reporters. “Hopefully he peacefully surrenders.”

The incident began after a woman called police saying her boyfriend had beat her. The suspect opened fire when officers attempted to arrest him.

Steven Martinez, who lives at the apartment complex, told the Orlando Sentinel he was going to bed when he heard gunshots.

Orlando Shooting 1

An Orlando police officer was shot after the shooter opened fire, then took four children hostage, police said. (FOX35 Orlando)

“I got scared, and I called 911,’’ Martinez recalled.

Another witness told FOX35 that police came to her door around 12:30 a.m. and said she needed to evacuate from the building. When the woman looked out her door, she told FOX35 she saw officers helping their injured partner into a police car.

Orlando Mayor Buddy Dyer tweeted on Monday: "Sending our community’s support and prayers to the @OrlandoPolice officer shot late last night. We appreciate our first responders who risk their lives each day to keep us safe."