NEW DELHI: Reliance Industries chairman Mukesh Ambani will now get 'Z' category protection, with the Union home ministry approving an armed squad of CRPF commandos for his proximate security less than two months after a threat letter, purportedly from the Indian Mujahideen, was hand-delivered at his office in Mumbai.

The letter is said to have threatened a terror attack at his Antilia residence at Altamount Road in south Mumbai.

Under 'Z' category security, Ambani will have pilot and escort vehicles with commandos armed with sophisticated weapons. Around two dozen personnel may be required to guard Ambani on a rotational basis.

The home ministry's decision to bring Ambani into the club of state-protected VIPs followed an inquiry by the Mumbai Police into the alleged letter. Sources said a threat analysis was also carried out by the Intelligence Bureau, which recommended round-the-clock security cover for the industrialist.

Home minister Sushilkumar Shinde, whose tenure has seen the approval of many new requests for VIP protection, approved Ambani's security a fortnight ago.

According to CRPF sources, the home ministry wrote to the paramilitary force soon after, asking it to take the responsibility of Ambani's protection with immediate effect. The CRPF, which is preoccupied with its primary task of manning the counter-Naxal grid, is in the midst of identifying and relocating its elite commandos to guard Ambani in Mumbai and during his travel to other parts of the country.

Incidentally, CRPF is not too enthusiastic about its diversion to VIP protection. "CISF is the designated central paramilitary agency for VIP protection. We are too busy with our duties in Naxal-hit zones," said an official, wondering why its commandos, trained in jungle warfare, should be diverted to VIP security.

The handwritten English letter delivered to Ambani in February had demanded the release of an IM operative named 'Danish'. However, it did not carry IM's logo, nor did it mention Danish's full name, though the alias is used by three men arrested in various cases.