The firing comes months ahead of the Maharashtra Assembly elections.
Baba Siddique, a former Maharashtra minister and member of the Ajit Pawar faction of the NCP, has died after being shot at in Mumbai's Bandra.
Sources said the shooters fired six bullets around 9.30 pm on Saturday near the office of Mr Siddique's son Zeeshan, who is the MLA from Bandra East. Two people have been arrested.
Baba Siddique was rushed to the Lilavati Hospital. Sources said four bullets hit the 66-year-old NCP leader and one of his aides also suffered a gunshot wound. The firing took place on Dussehra and came months ahead of the Maharashtra Assembly elections, which are expected to be held later this year.
Read | Baba Siddique Shooters Claim To Be From Lawrence Bishnoi Gang: Sources
Maharashtra Chief Minister Eknath Shinde said he had spoken to police and doctors at the hospital. "The incident is extremely unfortunate. There are reports that he (Mr Siddique) has died. Two people have been arrested, one from Uttar Pradesh and one from Haryana, while another is on the run. I have asked the police to take strict action and ensure no one takes law and order into their hands. A gang-war-like situation should not be allowed to resurface in Mumbai," he said in Marathi.
Deputy Chief Minister Devendra Fadnavis, who also holds the Home portfolio, has reached the hospital. Deputy Chief Minister Ajit Pawar wrote on X that he was shocked to know about Mr Siddique's death and that he had lost a good colleague and friend.
Mr Siddique, who was a three-time MLA from Bandra West, was associated with the Congress for 48 years and had quit the party in February and joined Ajit Pawar's NCP. Zeeshan Siddique was expelled from the Congress in August.
Expressing his shock, NCP Spokesperson Brijmohan Shrivastav told NDTV that Mr Siddique had not spoken about any threats from anybody.
Mr Siddique was elected as an MLA from the Bandra West constituency in 1999, 2004 and 2009 and served as a minister of state for food and civil supplies, labour and FDA between 2004 and 2008.
Read | When Baba Siddique Helped End SRK-Salman Khan Feud
The former MLA was known not just for his political acumen but also for hosting lavish parties. A cold war between superstars Shah Rukh Khan and Salman Khan was resolved at an 'iftar' party hosted by Mr Siddique in 2013.
Salman Khan and actor Sanjay Dutt have also reached the hospital.
Law And Order Questions
Expressing grief at the death of Mr Siddique, leaders of opposition parties also raised questions about law and order in Mumbai, asking how a politician who had Y-level security could be killed in public in an upscale area like Bandra.
NCP (Sharadchandra Pawar) President Sharad Pawar said people in the government should take responsibility and step down from their posts.
"The deteriorating law and order situation in the state is a matter of concern. It is sad that former state minister Baba Siddique was shot dead in the country's financial capital, Mumbai. If the Home minister and the rulers will take the state's vehicle forward with such leniency, it can be a warning sign for the common people. This not only needs to be investigated the rulers need to accept responsibility and step down from their posts. My heartfelt tribute to Baba Siddiqui and condolences to his family," he wrote in Marathi.
Congress leader and leader of the opposition in the Maharashtra Assembly, Vijay Wadettiwar, said the state government has supported criminals.
"The shooting and killing of former minister of state and former MLA Baba Siddique, who had Y-level security, is very shocking and tragic. I am praying for strength to his family in this difficult time. A big leader in the state has been shot like this. We keep saying that Maharashtra has become Uttar Pradesh. Mumbai was peaceful but such incidents are happening here now because there is no fear of the police in the city. The government has supported criminals," the Congress leader wrote in Marathi.
In his post on X, Deputy Chief Minister Ajit Pawar said the incident would be thoroughly investigated and strict action would be taken against the attackers.