Mumbai,  A man claiming to be an aide of absconding mafia don Dawood Ibrahim Kaskar called up "Matoshri" and demanded to speak to Maharashtra Chief Minister Uddhav Thackeray, officials said here on Sunday.

The caller, whose identity is not clear, reportedly called up at least twice on the landlines of "Matoshri" - the CM's private residence in Bandra east - on Saturday and said he wanted to speak to Thackeray, said Transport Minister Anil Parab.

"We have immediately informed the Mumbai Police to do whatever is necessary in the matter. The police will verify the antecedents of the caller and take whatever measures necessary for the safety and security of the CM," he told media persons this evening.

However, Parab categorically refuted reports in some sections that the caller allegedly issued threats to blow up the CM's residence, saying that there was no such thing.

Home Minister Anil Deshmukh said that the government has taken strong note of the development and the CID has been directed to look into the matter which has come up on the eve of the Monsoon Session of Maharashtra Legislature starting here on Monday.

Meanwhile, leaders of the ruling coalition - the Shiv Sena, the Nationalist Congress Party and the Congress - including Eknath Shinde, Parab, Balasaheb Thorat and Ashok Chavan, besides Mumbai Mayor Kishori Pednekar and others have reacted strongly to the incident and said the government will not be cowed down by any such threats to the CM.

All leaders have expressed full support to Thackeray while Pednekar said Shiv Sainiks will be ready to deploy their own ring of security around "Matoshri" if needed.

Taking serious note of the incident, the Mumbai Police have beefed up security around the Thackeray home as well as the Vidhan Bhavan complex at Nariman Point as a precaution.