Islamabad, Dec 19 (IANS): At least four suspects, including a woman, have been detained from Pakistan's Punjab province in connection with the Peshawar school attack that claimed 148 lives, Dawn online reported Friday.

The four were tracked through a SIM card which was reportedly used by terrorists during the attack on the military-run school.

The SIM was registered in the name of the woman who was taken into custody along with three others from Hasilpur in Bahawalpur district.

Inspector General (IG) of Police Khyber Pakhtunkhwa, Nasir Durrani, Thursday said the team constituted to investigate the attack is currently working on the available evidence, adding that it had a forensic lab replete with crime scene investigation officers who were helping to obtain evidence from the scene and analyse it.

He said that leads coming from initial investigations of the Peshawar school massacre extended beyond the country's border.

A senior military official said militants had been in direct communication with their handler in Afghanistan, Umar Naray, alias Umar Khalifa Adinzai - a well-known commander of the Tehreek-i-Taliban Pakistan's (TTP) Tariq Geedar group.

"He was directing the suicide bombers and the attack group," the official said.