Several militant commanders and their followers have split from the Pakistani Taliban, the second group this year to part ways with the umbrella organization in a move that analysts said Wednesday would further weaken the Taliban.

The development comes as Pakistan is waging an offensive against militants in North Waziristan, near Afghanistan's border.

The Pakistani Taliban, known as Tehrik-e-Taliban, are separate from the Afghan Taliban. They have been fighting for several years in an insurgency aimed at overthrowing the Pakistani government and installing their own harsh brand of Islamic law. The militants have killed thousands of people across the country in recent years.

This is the second time in four months that a faction has parted ways with the Pakistani Taliban after a South Waziristan branch split off in May.

In a video released late Tuesday, commander Maulana Qasim Khurassani said he and several of his associates and fighters, left the TTP and formed their own group, named Jamaat-ul-Ahrar.

Khurassani said they were inspired by the Afghan Taliban and their fight against U.S. troops in neighboring Afghanistan, as well as that group's reclusive leader Mullah Mohammad Omar.

Khurassani also said the split followed differences with the Taliban leadership but did not elaborate. The spokesmen for the Tehrik-e-Taliban Pakistan were not immediately available for comment.

Islamabad-based analyst Imtiaz Gul said the split will ultimately weaken the umbrella organization and work in favor of the military's offensive.

"The split is a major blow to the Tehrik-e-Taliban Pakistan, and the emergence of new group will further weaken it," Gul said.

Pakistan is a key ally of Washington in the war against terrorism, and the country's Prime Minister Nawaz Sharif re-launched government negotiations with the militants after coming to power last year. Sharif had tried to reach a deal and initially made peace talks a centerpiece of his policy.

But his peace efforts suffered a major blow when insurgents launched a deadly attack on the international airport in Karachi in June, killing 26 people. The Taliban claimed responsibility for the attack.

The assault in Karachi prompted authorities in June to launch the operation in North Waziristan, where the military says it has so far killed about 600 militants in the campaign.

Supporters of negotiations with the Taliban say it's the only way to end the cycle of violence. But critics say the militants have always used such deals to strengthen their ranks, regroup and strike back with more force.