A gunman accused of shooting and injuring three people remained holed up with at least one hostage in a standoff with police early Thursday, authorities said.

The gunman, whom police have not publicly identified, was armed with at least one handgun and one shotgun, said Lt. Chris Hebert of the Forest Hill police. Hebert said there could be more than one hostage.

"There are reports that there may be other people there, but we're not able to confirm it," Hebert said.

Police first responded Wednesday afternoon to reports of a shooting in a residential area of this Fort Worth suburb. Police arrived to find victims in the area and in a home, including one person who was critically injured, Hebert said.

The gunman then barricaded himself in the house and an hours-long standoff ensued.

Hebert said authorities had established "sporadic" contact with the gunman.

"That's a positive sign," said Tarrant County Sheriff's Office spokesman Terry Grisham, who added that there was no evidence that any hostages were injured. "We're cautiously hopeful and optimistic."

SWAT teams encircled the home overnight Wednesday, and authorities maintained an evacuation order for all neighbors within a block.

When the violence erupted, four people were taken to area hospitals, but Hebert said he did not know whether all four were gunshot victims.

Broadcast footage showed several children being escorted by police out of the back of a home and then across open fields. Several wounded adults were taken to ambulances by the same route and transported to hospitals.

About a dozen children at a home-based daycare facility four houses south of the besieged home were evacuated to safety, Hebert said.

An official at John Peter Smith Hospital in Fort Worth said Tonya Gilstrap was listed in fair condition. The extent of her injuries wasn't immediately available. The conditions of the others were not immediately available.

Gilstrap's husband, Alfredo Bueno, said that his wife was injured in the back and the head, apparently from the spray of a shotgun blast.

Brenda Jackson said the dispute started with an argument between her 43-year-old sister and her sister's estranged boyfriend, 57-year-old Joe Dixon.

"He and my sister were in an argument, and he tied her to the bed," Jackson told The Dallas Morning News for a story in its online editions. "I confronted him, and he said, "'If y'all call police, it's gonna be a war."'

Then, Jackson said, "he was standing next door to my yard, and everybody who was outside was shot."

Grisham said if authorities find that a hostage is hurt, "this could end very quickly."

"The longer these things go, the better the outcome," he said.