RCMP report a fire at Strathcona County Community Centre in the Edmonton-area suburb of Sherwood Park, but witnesses who spoke to CBC News say they heard an explosion at the building.​

Witnesses reported hearing an explosion at the building around 8 p.m. MT Tuesday.​

As of 7 a.m. Wednesday, all entrances to the community centre remained blocked off with road closure signs. RCMP vehicles with their lights flashing were helping to cordon off the area.

RCMP are holding a news conference at 11:30 Wednesday morning. Watch the news conference here.

An RCMP officer on scene told CBC News there are no active evacuations in place. The officer said police are focused on keeping people away from the parkade underneath the library.

In a Wednesday morning Facebook post, Strathcona County Mayor Rod Frank said the police matter is contained to the community centre building and there is no safety risk to the general public.

"Along with the community centre and county hall building, nearby schools and buildings have been closed today to give the RCMP room to conduct their investigation," Frank said.

'It wasn't a bang. It was a boom'

Sherwood Park resident Brent Oswald said he was on the second floor of the library when he heard a rumble from the parkade below.

"There was a very deep boom," Oswald said in an interview Wednesday with CBC Radio's Edmonton AM.

"It wasn't a bang. It was a boom and it shook the whole building."

Oswald said everyone filed out of the library as the fire alarms sounded and emergency vehicles arrived on scene. Oswald said he went to a restaurant across the street to watch the Oilers game.

It wasn't a bang. It was a boom. -Brent Oswald

When he came back outside, Oswald said the area was crawling with heavily-armed police.

"Things had completely changed," he said. "This wasn't just a couple of cops directing traffic.

"They were heavily armed and watching something ... and they just told me, 'Get out of here.'"

"I've never seen anything like that before."

Chelsea Thoen describes the 'huge bang' she heard from Strathcona County Community Centre on Tuesday night. 0:31

Oswald said he had parked his vehicle in the parkade before the evacuation. He said police haven't told him when he might be able to retrieve it.

"It was a massive explosion. It shook that place," he said. "I was on the second floor, so that's four storeys above the parking garage, and it's a reinforced concrete building.

"I don't even know if I have a car."

Chelsea Thoen was at the Strathcona County Library on Tuesday night when she heard a "huge bang."

"The whole building was shaking and you could barely hear anything except for everything shaking."

This is the scene at the corner of Festival way and Sherwood drive. Traffic heading south across from the mall still be rerouted. Heavy RCMP police presence at all entrances to the community centre. <a href="https://twitter.com/hashtag/ShPk?src=hash&ref_src=twsrc%5Etfw">#ShPk</a> <a href="https://t.co/srONauoNk1">pic.twitter.com/srONauoNk1</a> —@MinDhariwal Thoen said alarms started going off and those in the library began evacuating the building. She told CBC News that a firefighter told her to get out and "start running."

Police blocked off the roads in the area to investigate and were asking the public to stay away from the area due to safety concerns. The community centre complex contains the county's council chambers as well as the library, meeting rooms and outdoor plazas.

Chris Cummings's grandmother lives in Bedford Village, which is close to the community centre. He said he arrived around 7 p.m. and shortly after, he was told the building would need to evacuate due to a fire at the library.

Cummings said he helped 15 to 20 seniors leave for nearby St. Theresa Catholic School.

"When they first got there, a fire alarm went off in the building," Cummins said. "Two seconds later, an RCMP officer said, 'You guys have to start evacuating to a different door.' And the gentlemen had a very large weapon with him so we knew there was more than just a fire going on.

"It was a pretty quick evacuation from what it looked like. Some of them were just in their housecoats."

RCMP have blocked off roads in the area of the community centre. Police said the public should avoid the area due to safety concerns. (Raffy Boudjikanian/CBC)

Lorne Monaghan, principal at St. Theresa, said there were about 200 seniors at his school during the evacuation and most were in good spirits.

Ollie and Mel Miller were some of the folks evacuated to St. Theresa Catholic School from the Bedford Village retirement complex at 7 pm. They called their son, Michael, at 9:30 to pick them up. <a href="https://t.co/2Z1HReWDIj">pic.twitter.com/2Z1HReWDIj</a> —@jordanomstead "They're playing cards, we've got some pizza in and got them some coffee," Monaghan said Tuesday. "Don't know much about incident, but we've made it as smooth a night for them as we can."

Staff at Bedford Village were not available to comment but a message on the centre's phone line said that as of Nov. 7, the building's emergency evacuation had ended and it was "now safe" for residents to return to the centre.

In a statement, Strathcona County said the community centre will be closed Wednesday.

"The safety of our community remains the top priority of Strathcona County Council and emergency responders."

St. Theresa school and Salisbury Composite High School also will be closed Wednesday.

In a letter to parents, officials with Salisbury Composite High said the school would be closed to students and teachers the entire day due to an "incident" at the community centre.

"We anticipate the school will only be closed Wednesday but will advise all families when classes will resume," reads the letter.