Extensive police operation in Gosford CBD after several explosions and fire in offices, CCTV image released
In short:
NSW Police said there were reports of several explosions at offices in Gosford's CBD.
A man inside an office building said he saw someone throw an "incendiary device".
Police have released a CCTV image of a man they believe can assist investigators.
Police are investigating several explosions and a fire at offices in Gosford on the NSW Central Coast.
Dozens of employees were evacuated from the building on Donnison Street just after 2:30pm, with some reporting black smoke coming from the third floor.
In a statement NSW Police said there were reports of several explosions and a short time later officers were called to a fire at a separate office building on the same street.
"At the scene, police were told that a man entered the office before allegedly lighting a fire and fleeing the scene," it said.
Police have released a CCTV image of man they believe can assist investigators.
CCTV image of the man police want to speak to about the Gosford CBD building fire. (Supplied: NSW Police)
He is described as a man in his 60s with a short, chubby build who was wearing a black face covering, black shirt and dark pants, shoes and cap.
A Legal Aid NSW spokesperson said an explosion caused a small fire in the reception area of their Gosford office in Donnison Street and it has been temporarily closed.
Conditsis Lawyers director Michael Mantaj was inside the building at the time of the explosions.
"I didn't see the guy but someone threw an incendiary device," he said.
"All staff are accounted for. Fortunately no-one was injured."
Firefighters contained the blaze and there were no reports of injuries. (ABC News: Sean Tarek Goodwin)
Fire contained after offices evacuated
Fire and Rescue NSW (FRNSW) said the fire alarm had been activated at the building and a number of triple-0 calls were received.
Police said a 54-year-old employee was treated by paramedics for smoke inhalation.
Police and fire crews outside the Gosford office building. (ABC News: Shauna Foley)
FRNSW Superintendent Adam Dewberry said the fire had been contained and everyone had been accounted for.
He said there was a lot of smoke in the area shortly after the incident.
"We've got about 11 trucks and more than 40 firefighters battling this blaze, we do have water on the fire," he said.
"The fire is believed to be contained at this stage."
Firefighters out the front of a building on Donnison Street in Gosford. (ABC Central Coast: Sarah Forster)
Shianne Hubbard said she saw "a lot of police officers" as she drove past the scene with her mother.
"Living in the next suburb, it is very, very scary, considering my kids grow up here too," she said.
"You wouldn't think this is your average Thursday in Gosford, that's for sure."
Anthony Hopkins was down the road at work when he heard "a lot of noise and sirens".
"It's definitely crazy, not something that'd you expect," he said.
"It was nuts, there was cop cars and fire trucks lined up and down all the streets. You couldn't get in or out of the area."
Police have tapped off the building. (ABC News: Sean Tarek Goodwin)
Police said the office block in Donnison Street was expected to be locked down well into the night.
The ABC has been told crime scene officers have not even entered the building yet, due to high levels of carbon monoxide inside.
Police said the building needed to be left to naturally ventilate before they could proceed with their investigations.