The country's financial capital has been put on alert after a "terrorist threat" to attack the metropolis to avenge Israel's offensive in Gaza.
The "threat" was delivered in the form of a letter addressed to the Mumbai police commissioner Rakesh Maria and signed simply as "Mujahideen".
Maria confirmed receipt of the letter – delivered to the police control on Friday – and added that they were trying to ascertain its authenticity.
However, police was taking no chances in a city which has been at the receiving end of terrorist attacks several times.
"We are not taking any chance. All police stations, crime branch units and ancillary branches have been alerted," Maria said.
"We will take revenge for Gaza," the letter said and included a warning to Maria, who had successfully investigated the 1993 Mumbai serial blasts as a deputy commissioner of police (DCP), rounding up many members of the Dawood Ibrahim gang including brother of Tiger Memon, Yakub, and other members of his family.
The logistics for the blast, notably RDX explosives and grenades had been provided from across the border by the Inter Services Intelligence (ISI) of Pakistan.
"In 1993, you (Maria) got a chance. This time you won't. Stop us if you can," the letter added.
Following the arrest of some key Indian Mujahideen operatives last year, the disclosure about the threat to Maria, who was then heading the Maharashtra Anti Terrorism Squad (ATS) was ferreted out. Subsequently, Maria had been accorded Z category security, which is still continuing.
Israel had launched a ground offensive against the militant Hamas inside Gaza which left over a 1,000 dead in over a week.
A 24-hour truce also collapsed on Sunday with both sides resorting to heavy shelling across their borders.
Alert in Mumbai after 'threat' to avenge Gaza - Hindustan Times