With its ancient church and Gilbert Scott phonebox on the green, Worth Matravers on the Dorset coast is picture postcard England.

That was until yesterday, when locals found that war had been declared upon them by the Lobster Liberation Front. In a message on the internet, "buccaneers" of the LLF warned: "The war against the lobster industry has begun. "We will attack at any time. Pots will be smashed, boats sunk and sea-life liberated. No animal should be sacrificed for human greed, let alone boiled alive."

For Jonathan Lander the LLF is not amusing. Mr Lander, whose family have caught lobsters for five generations, was the front's first target.

The activists made their way to Chapman's Pool, the sheltered bay where he moors his boat, and in two attacks over a period of days smashed the engine, ripped the front off the boathouse, broke lobster pots and threw his catch back into the sea, causing about £10,000 damage.

The animal activists also went to his home in Worth Matravers and threw red paint over the walls.

Mr Lander, 42, a single father, only discovered the identity of his enemy this week when the LLF posted a statement on the internet. "Buccaneers from the Lobster Liberation Front attacked a boat-house belonging to Jonathan Lander," the message read.

"Grabbing a small boat that happened to be nearby, two of the pirates pushed off from shore and made their way across the Dorset bay. The cove was littered with buoys, which were all attached to large pots. These were dragged from the seabed and on to the boat.

"In total 30 lobsters and three large crabs were being stored in the pots. All of the animals had their claws bound with bands. The bands were cut, and the marine life returned to the sea, saved from the cruel fate in store for them."

The statement described how the "maritime warriors" had attacked the lobster boat. "The anchor cable holding the boat in the bay was cut, and the vessel was pushed out to sea. The last we saw of it it was sailing off into the sunset."

The message added: "Jonny Boy, we know where you live."

At the Square and Compass pub, in the village shop and all along the coast from St Albans head to Studland Bay, the lobster liberators appeared to be the only topic of conversation

Mr Lander said everyone was astonished by the attack. "I have never heard of anything like this in the whole industry before. At the end of the day I'm only producing food, we are the most sustainable fishery there probably is.

"We only take what is big enough and the rest go back in; it's not like trawler fishing. If these people have a problem with what we do they should have the decency to come and speak to us and not threaten my family and our livelihood."

Others in the industry wondered if they would be next. Rebecca Charron, who runs a coarse fishing centre near Corfe Castle, said: "I have never heard of anything so outrageous. This whole area revolves around animals and fishing. We live off the land."

Shellfish make up 80% of the catch, so the idea that lobsters are considered a suitable creature for liberation among activists is causing locals to review their security.

Jeff Lander, Jonathan's brother, said: "I've gone down to my boat every night since this attack, but you can't be there 24 hours a day."

At Swanage police station, PC Jonathan Maunder said: "I suspect Mr Lander was targeted because his boat was in an isolated position."