BEIRUT (AFP) - The Islamic State group on Sunday (April 17) vowed "revenge" over the killing of its former leader, calling on supporters to take advantage of war in Ukraine to stage attacks in Europe.

"We announce, relying on God, a blessed campaign to take revenge" over the death of Abu Ibrahim al-Qurashi and the group's former spokesman, an audio message attributed to the group and circulated on the Telegram messaging app said.

The group's new spokesman, Abu-Omar al-Muhajjir, also called on supporters to resume attacks in Europe, taking advantage of the "available opportunity" of "the crusaders fighting each other" - in reference to Russia's invasion of Ukraine.

The militant group's previous leader died in early February when he detonated a bomb to avoid capture during a US raid in northwest Syria, the White House and US defence officials said.

On March 10, the group confirmed his death, along with the group's former spokesman, naming Abu Hasan al-Hashemi al-Qurashi as the new leader.

Little is known about the new leader, who is the group's third chief since its inception. After losing their last territory under a military onslaught backed by the US-led coalition in March 2019, the remnants of ISIS in Syria mostly went into desert hideouts.

They have used such hideouts to ambush Kurdish-led forces and Syrian government troops. The militants also continue to mount attacks in Iraq.