INTRUDERS caused a 7,000 litre cloud of ammonia which hung over Ipswich after they used power tools to break into a disused factory.More than 20 firefighters had to deal with the leak of liquid ammonia, with the potential to blind, which spewed from a tanker in the disused Harris Bacon Factory just after 9.

INTRUDERS were to blame for a 7,000-litre cloud of ammonia which hung over Ipswich after they used power tools to break into a disused factory.

More than 20 firefighters had to deal with the leak of liquid ammonia, with the potential to blind, which spewed from a tanker in the disused Harris Bacon factory just after 9.20pm yesterday.

The fire crews wore special chemical protection suits as they cleared the hazard, which took until 12.45am today.

This morning managers were securing the site after the break-in, which caused thousands of pounds of damage.

People living near the Hadleigh Road site, between the Norwich and Felixstowe railway lines, would have smelt the ammonia.

Security guard Tudor Cooper, who arrived at the site at 7.30am, said: "They must have used power tools to break in. They levered up one of the doors, and turned on a tap from a tank containing ammonia.

"I have seen a man open a tank of ammonia and almost pass out. It can be very dangerous. The only thing to counter it is water. Thank God it rained last night."

The ammonia was used as part of the cooling process in the refrigerators for the bacon factory, which closed five years ago.

Mr Cooper said: "The intruders took a ladder from inside the factory and then went up another gantry ladder onto the roof. I don't know why they broke in."

The site, owned by Brightlingsea-based North East Essex Building Company, is awaiting redevelopment. Managing director Roger Raymond said: "I will be coming down to secure the site today. It is a disused building which we hope to redevelop."