KUALA LUMPER: Malaysian police is investigating a letter purportedly sent by the Islamic State (ISIS) militant group, threatening to kill Indian spiritual guru Sri Sri Ravi Shankar who was in Penang over the weekend.Inspector-general of police Khalid Abu Bakar confirmed that a letter was sent to meditation and spiritual guru over the weekend when he was in Penang for a yoga festival and talk attended by thousands in George Town and Batu Kawan.The police is trying to track the origin of the letter, which was posted locally to the office of Art of Living's Malaysian chapter in Shah Alam suburb near here.The letter, addressed to the manager of a Penang hotel where Ravi Shankar was staying during his visit, featured the black flag of the ISIS and a picture of a beheaded man.The letter reportedly warned the manager that his hotel would be "destroyed" if Ravi Shankar was allowed to "carry out his Hindu activities in Malaysia".Malaysia is a multi-ethnic Muslim majority country. The country's 28 million population includes eight per cent ethnic Indians, mostly Hindus.The letter also claimed that Ravi Shankar and his organization, Art of Living Foundation, were "meddling in the Islamic affairs of Iran and Iraq" and converting Muslims in the Middle East."If he steps foot in Malaysia, your hotel and venues of his activities will be destroyed and many thousands will die for him. We don't want Ravi Shankar to step into a Muslim country," the letter read.ISIS or IS is an al-Qaida splinter group and it has seized hundreds of square miles in Iraq and Syria. Al-Qaida has distanced itself from the group, chiding it for its lack of teamwork in its aggressive, brutal expansion.An Art of Living representative here said the guru was in Penang on Saturday for a yoga festival and addressed about 70,000 people at the Batu Kawan Stadium in a talk titled "Discourse, Music and Meditation".They confirmed that Ravi Shankar left for Singapore after a symposium yesterday.The case is being probed under Section 507 of Malaysia's Penal Code for criminal intimidation via anonymous communication, according to Penang police chief Abdul Rahim Hanafi.