Pakistan ? The Pakistani Taliban have appointed a new chief, militants said Saturday, selecting a top commander known for his ruthless efficiency in staging attacks, including a major hotel bombing and a deadly assault against the Sri Lankan cricket team.

The appointment of 28-year-old Hakimullah Mehsud could herald an increase in attacks as the group tries to prove it is still intact and operational, analysts say.

It comes after weeks of speculation and reported infighting among Taliban commanders to replace Baitullah Mehsud, the group’s former chief who was reportedly killed in an Aug. 5 CIA missile strike in northwestern Pakistan.

Several top Taliban commanders have insisted Mehsud is alive, but have provided no proof. U.S. and Pakistani officials are almost certain he was killed in the strike.

The government said it was investigating the reports that Hakimullah Mehsud had been chosen as the new Taliban leader.