The leader "was killed after direct clashes" with jihadist group Hayat Tahrir al-Sham in Idlib province, an IS spokesman said in a recorded message on its channels on the Telegram messaging app, without specifying when he was killed.

The spokesman announced the group's new leader -- its fifth -- as Abi Hafsan al-Hashimi al-Qurashi.

After a meteoric rise in Iraq and Syria in 2014 that saw it conquer vast swathes of territory, IS saw its self-proclaimed "caliphate" collapse under a wave of offensives.

The Sunni Muslim extremist group's austere and terror-ridden rule was marked by beheadings and mass shootings.

It was defeated in Iraq in 2017 and in Syria two years later, but sleeper cells still carry out attacks in both countries.

In November last year, IS said its previous leader, Abu Hasan al-Hashimi al-Qurashi, had been killed.

His predecessor, Abu Ibrahim al-Qurashi, was killed in February last year in a US raid in Idlib province.

The group's first "caliph", Abu Bakr al-Baghdadi, was killed, also in Idlib, in October 2019.