MATERIALS producer RMC has been attacked by activists campaigning against its role in aggregate dredging in the English Channel.
Vandals damaged locks and doors at the specialist's Leeds offices last month and daubed anti-marine dredging slogans across the building.
Last Friday, the firm's Norwich offices underwent a similar attack, with 'No Marine Quarrying' scrawled over walls, and door locks glued shut.
The vandalism is thought to be part of a fortnight of action which anarchists have conducted against it for its part in proposals to dredge aggregates from the sea bed in the east English Channel.
An RMC spokeswoman confirmed that police are looking into both incidents.
She said: 'Damage was caused at our Leeds office on August 27 and at our Norwich office on September 2, and both are currently being investigated.
We understand the action was in response to a call for a fortnight of action against marine quarrying.'
Trade body the British Marine Aggregate Producers Association has warned its other member companies of attacks but none has yet been hit by the activists.
BMAPA policy manager Richard Griffiths called the activists'claims unfounded.He said: 'These offences are in protest against dredging in the east English Channel which protesters claim will cause huge damage to the area.These are unfounded - all independent research shows the environmental impact of dredging in the area will be minimal.'
Mr Griffiths admitted there would be some impact but added that any operator who broke any operational rules faced having its dredging licence revoked.
He added: 'We have no concerns over the effectiveness of the operations.The environmental concern is understandable but a little misguided.'
RMC Marine, the division involved in the dredging, has recently stretched one of its fleet in anticipation of winning a licence to exploit the beds in the region.
Gravel beds in the area are in deeper water and further out to sea than other deposits it is currently dredging, and could hold enough reserves for 50 years.
RMC has also been the target of animal rights activists this year, when it supplied concrete to contractors building an animal research centre in Oxford.Main contractor Walter Lilly eventually pulled out and RMC halted deliveries after threats were made to shareholders.