A gunman shot dead on Tuesday a Pakistani militant commander who was a rival to Pakistani Taliban leader Baitullah Mehsud, police said.
The militant commander, known as Qari Zainuddin, had recently given statements to the media opposing Mehsud. He was killed in the northwestern town of Dera Ismail Khan, police said.
"I confirm that Qari Zainuddin has been shot dead," Salahuddin, superintendent of police in the city, told Reuters.
It was not clear who was behind the killing, he said.
Militants are split into several factions in northwest Pakistan, some of which are rivals.
The government has ordered the military to go on the offensive against Mehsud, who has been accused of a string of bomb attacks, including the assassination of former prime minister Benazir Bhutto in 2007.
The military has launched air strikes on Mehsud's bases in the South Waziristan region on the Afghan border and soldiers have been securing the main road into the mountainous region populated by ethnic Pashtun tribes.
The United States has offered a reward of $5 million on information leading to Mehsud's location or arrest.
Suspicion is likely to focus on Mehsud for Zainuddin's murder.
Zainuddin's strong statements against Mehsud in recent days had led to speculation authorities were encouraging him to stand up to his rival, Mehsud.