Islamabad: US Special Representative for Afghanistan Thomas West has raised concerns about increasing attacks by the banned outfit Tehreek-e-Taliban Pakistan (TTP) in Pakistan.

"The [increase in] attacks led by banned TTP is a challenge that Pakistan has been dealing with," said US Deputy Assistant Secretary for Afghanistan in a recent interview, as quoted by The News International newspaper.

Over US ties with the Afghan Taliban, West said: "I don't believe that there will be any practical partnership between the US and Taliban."

He pointed out that the Taliban's harbouring of slain Al-Qaeda chief Ayman al-Zawahiri was a clear violation of the Doha agreement.

The warning on TTP-led violence was given amid a sharp rise in attacks in recent months that has set alarm bells ringing in both Islamabad and Rawalpindi.

Pakistan media reports have flagged the growing presence of Tehreek-e-Taliban Pakistan in the northwest part of the country, following the Taliban takeover of Afghanistan in August last year.

Earlier this month, Pakistan's State Minister for Law Shahadat Hussain conceded that terror activities had increased sharply.

The highest number of terror incidents in Pakistan this year was recorded in September. An Islamabad-based think tank pointed to the resumption of attacks by the outlawed Tehrik-i-Taliban Pakistan.

The number of terror attacks increased in September compared to August this year, the Dawn said in an earlier report citing the Pakistan Institute for Conflict and Security Studies (PICSS).

September witnessed 42 militant attacks with an increase of 35 per cent compared to August. The Pakistani think tank also observed an increase of 106 per cent in violence in erstwhile Fata and Khyber Pakhtunkhwa (KP).

In August this year, the think tank said the militants carried out 31 attacks across Pakistan, in which 37 people were killed and 55 others injured.