The National Investigation Agency has received an email claiming that a person linked to the Taliban will carry out an "attack" in Mumbai, police said on Friday.
The probe agency's Mumbai office received the threat mail on Thursday, following which the city police and the Maharashtra Anti-Terrorism Squad were alerted, an official said.
According to the police, the email address used to send the threat message had "CIA" in it and the sender claimed that a person connected with the Taliban would carry out an attack in the city.
The IP (internet protocol) address of the sender has been traced to Pakistan, said the official.
A similar mail was sent to the federal agency last month as well. The police conducted a probe and did not find any substance in it, he said.
The police suspect this might be a mischief, as such mails were sent to the probe agency earlier as well, the official added.