Indonesian authorities are investigating the reported death in Iraq of a prominent Islamic State leader from Indonesia, who was defending the militant stronghold of Mosul during a U.S. backed military effort to dislodge the group.

A police spokesman in Jakarta told reporters on Thursday that Salim Mobarok al-Tamimin, also known as Abu Jandal al-Yemeni al Indonesi, was confirmed dead by his wife in Iraq, and relatives in Pasuruan in East Java. Abu Jandal, as authorities refer to him, was considered a key IS recruiter in Southeast Asia.

“We are making efforts to bring his body back,” Boy Rafli Amar, an inspector general of police, said in Jakarta.

According to initial information obtained by Indonesian authorities, Abu Jandal was killed in Mosul on Saturday. But the authorities have not determined the circumstances of his death.

A Kurdish military intelligence official in northern Iraq and a Mosul provincial council member declined VOA’s request for an interview. Indonesian counterterrorism officials say they have sent authorities to Iraq to gather more information.

“We know it is difficult to coordinate these efforts in a battlefield,” Amar said. “Coordination efforts with the authorities there (in Mosul) is also not that easy.”

The Indonesian foreign ministry is also attempting to gather more information in Iraq and Syria, where Abu Jandal reportedly operated under IS since 2014.

“None of the foreign missions (including in Indonesia’s) is operating,” said Arrmanatha Nasir, a spokesperson for the Indonesian foreign ministry.

“Besides, he never registered his arrival with the Indonesian Embassy in Baghdad or Damascus.”Abu Jandal, 39, traveled with his wife and two children to join the Islamic State in Syria in July 2014, with stops in Malaysia and Turkey, according to media reports.

In a YouTube video two years ago, Abu Jandal threatened to attack Indonesia’s top military commander, the National Police, counter-terrorism police, and Nahdatul Ulama – a traditionalist Sunni Muslim movement in Indonesia.

He appeared in the video, posted by IS’s al-?ayat Media Center, wearing a khaki Afghan outfit and encouraging sympathizers to travel to Iraq and Syria to join IS.

“To our brothers and sisters in Indonesia, we call on you once again to come here and perform jihad with the Islamic Caliphate,” he said.

As many as 384 Indonesians have joined IS, according to Indonesia’s counterterrorism agency. Most of those traveled to Syria and Iraq.

The Islamic State terror group remains a threat to Indonesia, the world’s largest Muslim country. IS claimed responsibility for carrying out coordinated bomb and gun attacks in Jakarta in January that left seven people dead, including five attackers.

VOA’s Rikar Hussein contributed to this report from Washington.