A gunman holding a five-year-old boy hostage in a bunker continued to keep police at bay in a siege that began when he killed a school bus driver and dragged the child away.
SWAT teams took up positions around the gunman's rural property in Alabama, as police negotiators tried to secure the boy's safe release.
The gunman, identified by neighbours as Jimmy Dykes, a 65-year-old retired lorry driver, was known locally as a menacing figure who once beat a dog to death with a lead pipe, threatened to shoot children for setting foot on his property and patrolled his garden at night with a flashlight and a shotgun.
He had been due to appear in court yesterday morning accused of shooting at his neighbours in a dispute over a speed bump last month.
The stand-off along a red dirt road began on Tuesday afternoon US time, after the gunman boarded a stationary school bus filled with children in the town of Midland City. Sheriff Wally Olson said the man shot the bus driver when he refused to hand over the child and dragged the boy away.
"As far as we know there is no relation at all. He just wanted a child for a hostage situation," said Michael Senn, a pastor who helped comfort the traumatised children after the attack.
The bus driver, Charles Poland, 66, was hailed a hero who gave his life to protect the 21 children on the bus.
The boy's classmates, their parents and other members of the small community gathered in several churches and held a candlelight vigil in the town square last night to pray for Mr Poland and the boy's safety.
Authorities gave no details on the siege and it was unclear if Dykes made any demands from his underground bunker, which resembled a tornado shelter.
The sheriff said negotiators continued talking to the suspect and "at this time we have no reason to believe that the child has been harmed".
About 50 law enforcement vehicles were clustered at the end of a dirt road near where Dykes lived in a small mobile home. Nearby homes were evacuated after authorities found what was believed to be a bomb on his property.
State congressman Steve Clouse, who met authorities and visited the boy's family, said the bunker had food and electricity and the youngster was watching TV. He said police were communicating with the gunman.
At one point, authorities lowered medicine into the bunker for the boy after his captor agreed to it, Mr Clouse said. He said he did not know what the medicine was for or whether it was needed urgently.
Chris Voss, a former international kidnapping negotiator for the FBI, said negotiators at the scene should remain patient and calm, resisting the urge to force a quick resolution.
"Getting what you want is not the same as getting even," said Mr Voss, whose firm, the Black Swan Group, now consults on high-stakes negotiations. "Flooding the zone will not save lives."
Mike and Patricia Smith, who live opposite Dykes and whose two children were on the bus when the shooting happened, said their youngsters had a run-in with him about 10 months ago.
"My bulldogs got loose and went over there," Mrs Smith said. "The children went to get them. He threatened to shoot them if they came back."
"He's very paranoid," her husband said. "He goes around in his yard at night with a flashlight and shotgun."
Mrs Smith said her children told her what happened on the bus.
Two other children had just been dropped off and the Smith children were next. Dykes stepped on to the bus and grabbed the door so the driver could not close it. Dykes told the driver he wanted two boys, six to eight years old, without saying why.
According to Mrs Smith, Dykes started down the aisle of the bus and the driver put his arm out to block him. Dykes fired four shots at Mr Poland with a handgun.
"He did give his life, saving children," Mr Smith said.
Mrs Smith said her daughter, a high school pupil, began corralling the other children and headed for the back of the bus while Dykes and the driver were arguing. Later, Mrs Smith's son ran inside his house, telling his mother: "The crazy man across the street shot the bus driver and Mr Poland won't wake up."
Mrs Smith ran over to the bus and saw the driver slumped over in his seat. Her daughter used another child's mobile phone to call emergency services.
Another neighbour, Ronda Wilbur, said Dykes beat her dog with a lead pipe for coming on to his side of the dirt road. The dog died a week later.
"He said his only regret was he didn't beat him to death all the way," Ms Wilbur said. "If a man can kill a dog, and beat it with a lead pipe and brag about it, it's nothing until it's going to be people."
Dykes was due to appear in court today to face a charge of menacing some neighbours as they drove near his house weeks ago. Claudia Davis said he yelled and fired shots at her, her son and her baby grandson over damage Dykes claimed their pick-up truck did to a makeshift speed bump in the dirt road. No-one was hurt.
"Before this happened, I would see him at several places and he would just stare a hole through me," Ms Davis said.
"On Monday I saw him at a laundromat and he seen me when I was getting in my truck, and he just stared and stared and stared at me."