MIDLAND CITY, Alabama (AP) - Authorities said Saturday that still have an open line of communication with an Alabama man accused of abducting a 5-year-old boy and holding him hostage in a bunker, and they thanked the suspect for taking care of the child as the standoff marked its fifth day.

Dale County Sheriff Wally Olson said in a briefing with reporters that Jimmy Lee Dykes has told them he has blankets and an electric heater in the bunker. Olson said Dykes has allowed authorities to deliver colouring books, medication and toys for the boy.

"I want to thank him for taking care of our boy," Olson said. "That's very important."

Authorities say Dykes shot a school bus driver Tuesday and took the boy to the bunker on his property in rural Midland City.

Olson would not say whether Dykes has made any demands. Olson added that he is limited in the details he can release.

FBI spokesman Jason Pack said Saturday that officials were working to establish a command centre near the bunker.

Negotiators were still trying Saturday to persuade Dykes to surrender. Police have said they believe the Vietnam-era veteran fatally shot a school bus driver Tuesday, and then abducted the boy from the bus and disappeared into the home-made bunker.

While police were mostly staying mum about the delicate negotiations, it fell to neighbours to fill in the blanks about Dykes, described by some as a menacing figure with anti-government views.

One of Dykes' next-door neighbours said the suspect spent two or three months constructing the bunker, digging several feet into the ground and then building a structure of lumber and plywood, which he covered with sand and dirt.

Neighbour Michael Creel said Dykes put the plastic pipe underground from the bunker to the end of his driveway so he could hear if anyone drove up to his gate. When Dykes finished the shelter a year or so ago, he invited Creel to see it - and he did.

"He was bragging about it. He said, `Come check it out," Creel said.

He said he believes Dykes' goal with the standoff is to publicise his political beliefs.

"I believe he wants to rant and rave about politics and government," Creel said. "He's very concerned about his property. He doesn't want his stuff messed with."

Police have used a ventilation pipe to the bunker to talk to the man and deliver the boy medication for his emotional disorders, but they have not revealed how often they are in touch or what the conversations have been about. Authorities waited until Friday to confirm the suspect's identity.

While much of what is going on inside the bunker remains a mystery, local officials who have spoken to police or the boy's family have described a small room with food, electricity and a TV. And while the boy has his medication, an official also said he has been crying for his parents.

Meanwhile, Midland City residents held out hope that the standoff would end safely and mourned for the slain bus driver and his family. Candlelight vigils have been held nightly at a gazebo in front of City Hall. Residents prayed, sang songs such as "Amazing Grace" and nailed homemade wooden crosses on the gazebo's railings alongside signs that read: "We are praying for you."

"We're doing any little thing that helps show support for him," said 15-year-old Taylor Edwards.

Former hostage negotiators said authorities must be cautious and patient as long as they are confident that the boy is unharmed. Ex-FBI hostage negotiator Clint Van Zandt advised against any drastic measures such as cutting the electricity or putting sleeping gas inside the bunker because it could agitate Dykes.

The negotiator should try to ease Dykes' anxieties over what will happen when the standoff ends, and refer to both the boy and Dykes by their first names, he said.

"I want to give him a reason to come out," Van Zandt said.