MIDLAND CITY, Alabama (CNN) -- It's been a long week in Midland City.
Last Tuesday, police say, a man named Jimmy Lee Dykes boarded a Dale County school bus and demanded the driver hand over two children.
The driver, Charles Albert Poland Jr., refused, blocking access to the bus's narrow aisle as at least 21 children escaped out of the back emergency door, authorities said.
Police say the gunman killed Poland, then grabbed a kindergartner before barricading himself and the boy inside a nearby bunker he had built.
Authorities held a news conference Monday afternoon, but as they have since the standoff began, they declined to offer many details of what was happening.
"We're doing everything humanly possible to resolve this safety and bring this child home," Dale County Sheriff Wally Olson said at the news conference. He said deliveries of food, medication and other comfort items continue.
School resumes nearby
Plenty of police were on hand Monday as schools in neighboring Ozark, Alabama, reopened for the first time since the incident.
Dale County schools remained closed but were to reopen on Tuesday, the district said.
In Ozark, school officials decided to begin strictly enforcing a 15-foot safety zone around school buses required by state law. The law prohibits any unauthorized adults, including parents, from approaching within 15 feet of a school bus stop. If an unauthorized adult gets too close, bus drivers are supposed to close bus doors or drive away, if necessary, school officials said.
The abduction has rattled the nerves of many parents, said Rebecca Jules-McQuet, whose 5-year-old daughter returned to school Monday.
"You think about it every night when you go to bed that that little boy is not in his bed, with his mom and dad," she said. "It's heart-wrenching.
Dozens of police staffing a command post about a half-mile from the bunker where the child is being held appeared to have settled into a 12-hours-on, 12-off routine.
Local, state and federal investigators handling the standoff do their work either inside trailers at their command post or at the scene, beyond a closed road leading to Dykes' property.
A helicopter remains on standby for a possible medical evacuation. Another is there to transport officials to the scene.
Officials haven't said much about what is going on, or what -- if anything -- Dykes wants.
"Based on our discussions with Mr. Dykes, he feels like he has a story that's important to him, although it's very complex," Olson said Monday. He didn't elaborate.
An FBI spokesman said Sunday that authorities continue "to maintain an open line of communication with Mr. Dykes."
Conditions in the bunker
The boy suffers from Asperger's syndrome and attention deficit disorder, State. Rep. Steve Clouse said.
Dykes told authorities that he has blankets and a heater in the bunker, and authorities have previously said the bunker -- built 4 feet underground -- has electricity.
Authorities haven't said how they are communicating with Dykes. It could be through a plastic ventilation pipe that leads from the bunker.
"Throughout the day, Mr. Dykes has continued to allow us to deliver food, medicine and comfort items to the child. Some of those items we have delivered include a red Hot Wheels car and some Cheez-Its crackers," FBI spokesman Paul Bresson said Sunday.
It's not clear how those supplies are being delivered.
Meanwhile, residents and business owners in Midland City have put up blue, red and black ribbons in support of the boy and Poland. Blue and red are the local school colors, and black is in honor of the slain bus driver.
New details about Dykes
The U.S. Navy confirmed Monday that Dykes served in the military from 1964 to 1969.
Naval records list him as an aviation maintenance administrationman third-class who served with units based in California and Atsugi, Japan. The job entails clerical work related to aircraft and aircraft maintenance, according to the Navy's job description.
Neighbors and officials have described Dykes as a survivalist with "anti-government" views.