KUALA LUMPUR - A petrol bomb was thrown on Tuesday at the office of a senior politician in Malaysia's opposition-ruled Penang state, after he described a visiting fiery Islamic preacher as "Satan".

State officials said no one was injured and no damage caused in the early-morning attack after the firebomb landed on the centre's metal shutters.

State Deputy Chief Minister P Ramasamy said the attack may have been prompted by his Facebook post over the weekend about preacher Zakir Naik. "It could possibly be related to my comment on Zakir as Satan," he told AFP.

His posting was not directed against Islam or Muslims but against "this particular person", Ramasamy said in a statement.

"I regret the use of the word 'Satan' which has caused uneasiness and unhappiness among Muslims in Malaysia," Ramasamy said, adding that the word was later deleted.

Ramasamy, who is also the Penang Hindu Endowment Board chairman, had spoken out against a planned programme by Zakir's son, also an Islamic preacher, in Penang state on April 15.