MUMBAI: The Western Naval command headquarters has alerted the city police about the threat of a bomb attack on the US consulate here on July 21. The intelligence was shared with reference to an anonymous letter received by the consulate-general and American Centre in Kolkata, threatening to attack both places.

A copy of the single-page letter was passed on by Sanjay Kumar, command intelligence officer, western naval command. The letter has 'Al-Jihad' written on top, much like a logo or the name of an organization. It said US consulate officials are the targets and told the Americans to vacate the consulates. It also said, "We shall carry out blasts in public places and railway stations of Hyderabad, Bangalore and Mumbai in July this year."

It was unclear when the US consulate received the letter and why July 21 was chosen. Al-Jihad is not known to intelligence agencies but they are taking the threat seriously as terror outfits are known to hide under various names. The input has been shared with the Intelligence Bureau headquarters and its wings in Hyderabad, Kolkata, Bangalore and Mumbai.

The state anti-terrorism squad (ATS) also issued a terror alert, saying the Indian Mujahideen (IM) could target several places to avenge the conviction of and death penalty for its operative, Himayat Mirza Baig, in the German Bakery bomb blast case.

Amitesh Kumar, deputy inspector general of police, ATS, in a two-page alert stated, "In view of the death penalty to Himayat Baig in the German Bakery bomb blast case and the recent blast in Bangalore, retaliation cannot be ruled out. IM can possibly launch a fresh terror strike."

Kumar said of the likely targets that need special attention are the ones that have already been reconnoitered by terrorists, as revealed during interrogation of the CIA spy-turned-Lashakar-e-Taiba loyalist, David Headley. A National Investigation Agency team had interrogated Headley in the US.

The places mentioned in the hit list of terrorists include the Nashik police academy, Deolali army cantonment, the Osho ashram, ABC Farm, Hard Rock Café, Oakwood Hotel, Koregaon Park Plaza, J M Road, North Main Road in Pune, Gold Adlabs, Hinjewadi, and the RSS headquarters in Nagpur.

A police officer said all the locations have been provided additional security. However, while security and intelligence agencies have been sending out terror alerts often, their credibility is in doubt. Many senior officers say they don't even read the alerts. While intelligence agencies claim it's their job to pass on information, several city police officers contend that the information given is often difficult to establish or act on.