ISLAMABAD - At least three security personnel were killed and five others injured on Monday morning in an attack at the Federal Constabulary's headquarters in Pakistan's northwest Khyber Pakhtunkhwa provincial capital of Peshawar, police said.

Inspector General of Police of Khyber Pakhtunkhwa Zulfiqar Hameed told the media that a suicide bomber exploded his jacket at the main gate of the Federal Constabulary headquarters, formerly known as Frontier Constabulary.

Following the attack, two terrorists entered the initial area of the headquarters, but guards on duty shot both of the terrorists dead on the spot, said the police chief.

The police chief added that one of the two killed terrorists was a suicide bomber, and his explosive-laden jacket exploded after the firing.

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Eyewitnesses told Xinhua that they heard intense firing after two blasts took place in the area.

Police, security forces, and rescue teams rushed to the site and shifted the injured to a nearby hospital.

Police have blocked the roads leading to the area and asked citizens to be vigilant and avoid travelling unnecessarily in the region.

Security forces have launched a search and clearance operation in the area as well as inside the headquarters.

No group has claimed the attack yet.

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The Frontier Constabulary, which was formerly tasked with securing the tribal belt in the northwest region, was renamed to Federal Constabulary under an ordinance in July this year, with its jurisdiction extended to the entire country.

Later in September, the federal government announced plans to shift the headquarters of the Federal Constabulary from Peshawar to the country's capital Islamabad.

Interior Minister Mohsin Naqvi told the media in September this year that the aim to shift the headquarters was to modernize the force and improve coordination with other federal institutions.

Pakistani Prime Minister Shehbaz Sharif strongly condemned the terrorist attack, saying that we will foil the nefarious designs of terrorists who attack Pakistan's sovereignty.