Al-Qaida leader Ayman al-Zawahri purportedly pledged his group's allegiance to the new leader of the Taliban following the death of Mullah Mohammad Omar in an audio recording that surfaced Thursday.

The pledge came in a 10-minute recording that was circulated on social media and was later carried by the U.S.-based SITE Intelligence Group. It was the first recording from al-Zawahri in almost a year.

The recording, which resembles previous audio clips released by the al-Qaida leader, eulogizes Mullah Omar, who sheltered al-Qaida in the years leading up to the Sept. 11, 2001 attacks when the Taliban ruled Afghanistan. Osama bin Laden and his followers considered Mullah Omar the Commander of the Faithful, an ancient title once held by the successors of Islam's Prophet Muhammad.

"He was an emir who defied the polytheists and the pagans," al-Zawahri said. He called Mullah Omar the first leader to establish a Muslim emirate after the fall of the Ottoman empire, and the recording includes a clip of bin Laden pledging allegiance to Mullah Omar.

Afghan authorities late last month announced that Mullah Omar, a reclusive leader almost never seen in public, had died more than two years ago in a Pakistani hospital. The Taliban later confirmed his death and appointed his longtime deputy Mullah Akhtar Mansoor to succeed him.

But Mullah Omar's family has rejected the decision, and it appears to have widened a rift within the Taliban between those who favor Pakistan-brokered peace talks and those who want to continue waging their 14-year insurgency.

Although al-Qaida and the Taliban were closely allied in the 1990s, the groups have long diverged in their focus, with the Taliban aiming to establish and preserve Islamic rule in Afghanistan and al-Qaida harboring global ambitions and committed to attacking the West.

Al-Zawahri urged Mullah Mansoor to follow in the footsteps of his predecessor. "We are your soldiers and your supporters and a brigade of your brigades," al-Zawahri said.