Four people are in hospital following a suspected chemical leak at a brewery.
Police, fire and ambulance crews were called to the Carlsberg plant in Northampton, at about 12:30 GMT.
It is believed to be an ammonia leak, a fire officer has told the BBC. Carlsberg has said there was a "safety incident" at its Bridge Street site.
Northampton General Hospital said it is treating four people, and the ambulance service's Hazardous Area Response Team (HART) has been at the scene.
The East Midlands Ambulance Service said the team was with "several" ambulance crews to "assess patients" and had "specialist training and equipment to deal with chemical-related incidents".
An air ambulance has been spotted taking off from the scene and people have been seen leaving with tissues over their mouths.
Carlsberg said in a statement: "Earlier today there was a safety incident within the Carlsberg UK brewery on Bridge Street, Northampton.
"At this stage the emergency services are on site and are managing the situation.
"We will provide further updates as soon as we are in position to do so."
A spokesman for the firm added: "Brewery employees have been taken to a safe space on the site and office employees are free to leave as they wish".
Northamptonshire Police tweeted that six fire engines were at the scene to "secure" the site, but that no cordons or road closures had been set up.
However, they have warned motorists to avoid the area to "reduce congestion".
BBC NEWS.
Police, fire and ambulance crews were called to the Carlsberg plant in Northampton, at about 12:30 GMT.
It is believed to be an ammonia leak, a fire officer has told the BBC. Carlsberg has said there was a "safety incident" at its Bridge Street site.
Northampton General Hospital said it is treating four people, and the ambulance service's Hazardous Area Response Team (HART) has been at the scene.
The East Midlands Ambulance Service said the team was with "several" ambulance crews to "assess patients" and had "specialist training and equipment to deal with chemical-related incidents".
An air ambulance has been spotted taking off from the scene and people have been seen leaving with tissues over their mouths.
Carlsberg said in a statement: "Earlier today there was a safety incident within the Carlsberg UK brewery on Bridge Street, Northampton.
"At this stage the emergency services are on site and are managing the situation.
"We will provide further updates as soon as we are in position to do so."
A spokesman for the firm added: "Brewery employees have been taken to a safe space on the site and office employees are free to leave as they wish".
Northamptonshire Police tweeted that six fire engines were at the scene to "secure" the site, but that no cordons or road closures had been set up.
However, they have warned motorists to avoid the area to "reduce congestion".
BBC NEWS.