For a brief moment it looked as if the antiG8 protesters had won a battle, if not the war.

They failed to punch a hole in the eight-mile (13km) steel and barbed-wire fence that was guarding world leaders. But for a few hours they did come within 20 yards before being beaten back by riot police firing high-powered jets of water.

Perhaps, just perhaps – much depended on the sea winds around Heiligendamm – President Bush was able to hear them shout: “No justice, no peace!”

It was an instructive piece of guerrilla protest, the result of a year of tactical planning. “We successfully captured two access roads to the G8 summit,” Christoph Kleine, a leading member of the radical Interventionist Left, said. “We are very satisfied.”

The protesters plan to stay for 24 hours within about 200m (650ft) of the leaders’ compound, mimicking a medieval siege. “We don’t have to storm the wall. That wall will always be the symbol of how the G8 is excluding the rest of the world,” he said.

The protesters used what is known as the Five Finger strategy, borrowing from the guerrilla warfare textbooks of Mao Zedong and Che Guevara.

Two wings of the protest movement managed to paralyse stretches of the motorway linking Rostock airport to the G8. A third detachment blocked the narrow-gauge railway track on which the vintage Molli locomotive attempted to ferry journalists into the G8 security compound to meet José Manuel Barroso, the European Commission President. The journalists eventually had to be transported by sea.

One of the key diversionary tactics involved a group known as the Rebel Clown Army. They had their first real outing at the Gleneagles G8 summit two years ago and, in the current skirmishes, are fielding some 500 people with red noses and floppy boots.

Typically they surround police vans, squirt them with water pistols, jump on car bonnets to distract officers from other, more serious, protest actions. Three – Matthias, Daniel and Kati – drove a police checkpoint to distraction with bad jokes and a mock silver-foil machinegun.

“Feeling cold then?” Daniel asked as one policeman started to put on his armour. “Take us with you, we’ll cheer you up,” Matthais said, pretending to vomit in their laps.

Later police claimed that militants had been shedding their black shirts and donning clown masks to come up close and cause injury. A spokesman said that eight officers had been treated for skin irritations caused from a fluid shot.

“That’s the funniest thing I’ve heard all day,” said the Rebel Clown Army spokesman, Matthias Häberlein. “We use the purest of soap bubbles.” He added: “Of course anyone can dress up as a clown. It’s a human right.”

Clowns, Greens, blackshirted radicals, gay-rights activists and antinuclear campaigners prepared for a vigil within loudspeaker distance of the G8 leaders last night. The idea, they said, was to make sure that they did not sleep easy.

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