Extra police officers have been stationed in Mumbai over fears of unrest after a right-wing leader called for Hindus to play religious hymns outside mosques in protest against Azaan (call for prayers) on loudspeakers. Raj Thackeray, the politician and founder of Maharashtra Navnirman Sena, has been campaigning against the use of loudspeakers for Azaan in India’s financial capital and had given an ultimatum to authorities to remove the amplifiers. He called upon Hindus to play <i>Hanuman Chalisa</i> — a devotional recitation dedicated to monkey God Hanuman – every time the Muslim call to prayer was recited from mosques on Wednesday. “I appeal to all Hindus that on May 4, if you hear the loudspeakers blaring with Azaan, in those very places play <i>Hanuman Chalisa</i> on the loudspeakers. That’s when they will realise the hindrance of these loudspeakers,” a statement by Mr Thackeray said. Most mosques in the city kept loudspeakers off during the morning Azaan on Wednesday and <i>Hanuman Chalisa</i> was heard being played outside only some. Some members of Mr Thackeray’s party played devotional Hindu hymns outside the headquarters of the ruling Shiv Sena party and local commuter trains. In neighbouring Thane, police said some party supporters played the song on a loudspeaker in the city. Police detained about 250 workers and leaders from the party across the state as a precautionary measure. Mr Thackeray insists his demand for a ban on loudspeakers is not religious but social, citing a Supreme Court order. The court has banned loudspeakers from 10pm to 6am but permits their use until midnight on festive occasions for 15 days a year. He urged Hindus to inform police and lodge complaints if they are disturbed by the sound of Azaan as he says it breaches the court’s ruling. Right-wing Hindu political and radical groups had previously launched similar drives in India, including demands of a ban on halal food, the hijab and boycotting Muslim businesses. The campaigns have often led to violent clashes, including one in Rajasthan’s Jodhpur city on Eid, when Hindus and Muslims clashed over hoisting their respective religious flags. Nearly 100 people have been arrested and mobile internet services cut as a curfew remains in parts of the district. A wave of violence last month spread across a dozen Indian states during Hindu festivals, including street clashes in the capital Delhi.