LONDON (AFP) - Prince Charles has spoken out against the "apparent rise in anti-Semitism" in Britain and warned of "other poisonous and debilitating forms of intolerance" after a series of attacks on mosques.

He was speaking on Monday at a London event celebrating Jonathan Sacks, Britain's outgoing Chief Rabbi.

"Running throughout your time as Chief Rabbi has been that all-important principle of which this country has long been an exponent, the principle of tolerance," he said.

"I sometimes fear not enough recognition is given to the role of the faith communities in the life of our country in promoting such a critical principle, and I join with you, in mounting anxiety, at the apparent rise in anti-Semitism, along with other poisonous and debilitating forms of intolerance."

A police investigation is underway after the discovery of a home-made bomb at a mosque in central England, the latest in a series of reprisals for the apparently Islamist-inspired murder of soldier Lee Rigby in London.