A spokesman for the group said Maulana Fazlullah, who earlier led Taliban fighters in Swat Valley, was currently leading the attacks from Afghan soil.
Fazlullah, also known as Mullah Radio, escaped to Afghanistan when the Pakistan Army launched an operation in Swat in 2009.
"Maulana Fazlullah is leading TTP attacks from Afghanistan's border provinces and is in touch with fighters in Malakand division," Sirajuddin, the spokesman for the Pakistani Taliban chapter in Malakand area of Khyber-Pakhtunkhwa, said on phone from an undisclosed location.
"We regularly move across the porous border," Sirajuddin said. He claimed Fazlullah was leading over 1,000 diehard fighters.
Pakistani officials believe top Taliban commanders, including Fazlullah, Maulvi Faqir and Waliur Rehman, and hundreds of their loyalists fled military offensives in Swat and Bajaur and Mohmand Agencies to seek shelter in Afghanistan.
Contrary to Pakistani claims that the Taliban cadres escaped to Afghanistan over the past few years, Sirajuddin said the commanders and fighters fled to Afghanistan in recent months and were now settled in that country's border regions.
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Till recently, the government of President Hamid Karzai was in denial about the Pakistani Taliban's bases in Afghanistan.
However, Kabul has now conceded the presence of "some TTP militants" in the border regions, according to a senior Pakistani official.
Thirteen Pakistani soldiers were killed in a cross-border attack launched by Taliban fighters in Upper Dir area on Sunday.
Seven soldiers were beheaded by the Taliban fighters.
Pakistan's Foreign Office called in the Afghan Deputy Chief of Mission yesterday and lodged a strong protest over the incident.