Harkat-ul-Jihad al-Islami has threatened it will attack the Foreign Office, the Foreign Secretary, Pakistan's High Commission in New Delhi and High Commissioner Shahid Malik if its demand is not met, the Dawn newspaper quoted police sources as saying.
The terrorist group warned the Foreign Office to ask Pakistan's High Commission in New Delhi to stop sharing details and information about HuJI with the Indian government, the report said.
The warning was given through a handwritten letter addressed to Foreign Secretary Salman Bashir, it said.
The letter in Urdu was sent by mail to Bashir's residence in Sector F-6 of Islamabad a few days ago.
Senior police officers met Bashir to inquire about the letter. Police officers analysed the letter and confirmed that it had been sent by HuJI, the daily quoted its sources as saying.
Police also found out the letter was mailed from within Islamabad. A team of police commandos has been deployed at Bashir’s residence and he has been provided police protection.
A strict vigil was mounted around Bashir's house, the Foreign Office and roads leading to the two places.
Ilyas Kashmiri, the commander of HuJI who is believed to have masterminded the Mumbai attacks and a terrorist assault on a naval airbase in Karachi, was reportedly killed in a US drone attack in South Waziristan tribal region last month.
