A STRONG smelling gas which came from a tanker moored offshore sparked hundreds of calls from householders in Lowestoft who feared they were at risk of fire because their pipes were leaking.

A STRONG smelling gas which came from a tanker moored offshore sparked hundreds of calls from householders in Lowestoft who feared they were at risk of fire because their pipes were leaking.

School pupils, shop workers and council staff were evacuated from buildings on Monday lunchtime after a gas smell wafted over the town centre.

It was soon found that the smell was coming from a tanker venting its pipes offshore, but National Grid Transco, which deals with reports of gas leaks, had already received more than 500 calls from the Lowestoft area.

Yesterday (Tuesday) National Grid Transco set up a drop-in caravan on the town's seafront offering advice to residents and in order to be on hand to check out any more calls which were received.

A spokesman said: 'We had to respond to every one of those calls as if it was a gas leak, we could not just assume it was the same smell coming from the boat.'

As well as reports of suspected leaks, Suffolk Fire Service had 13 calls in the early afternoon about a strong smell of gas and concerns about it sparking a fire.

A spokesman for the fire service said: 'We had calls from two schools and 11 individual residents. As we knew what was going on, we told the people about this smell, but we treated them all as normal fire reports and dealt with them as we usually would.'

The Health Protection Agency (HPA) confirmed yesterday that the fumes were a naturally-occurring, colourless gas. He said: 'The gas being released was methyl mercaptan, also known as methanethiol, which is most commonly added to household gas supplies to make it smell the way it does.'

Although the gas can be toxic at high concentrations, the HPA spokesman confirmed that the fumes in Lowestoft posed no risk to the public.

A spokesman for the Marine and Coastguard Agency (MCA) said that ships are not allowed to vent their tanks when in port and that the vessel involved was told to move further offshore.

She said: 'The boat was obviously alongside the shore and one of our surveyors went on board and told them that they would have to go further offshore before continuing. They have to be eight miles offshore before they can do this.'

On Monday afternoon, the strong smell reached the centre of Lowestoft and buildings in London Road North, including fashion store New Look and Waveney District Council's Marina customer services centre, were evacuated at about 1.30pm because staff reported smelling gas.

Roman Hill and Woods Loke Primary Schools and Foxborough Middle School also evacuated pupils, and staff at Rishton House in Clapham Road South were cleared out of the building while the source of the smell was investigated.

It drifted northwards along the coast and there were reports of a smell of gas in Gorleston and Yarmouth by about 6pm.

Due to a change in wind direction and the boat moving further offshore, fewer calls about the smell were reported yesterday but a number of calls were received from further down the coast in Southwold.