Hamas chief Ismail Haniyeh, whose assassination in Tehran earlier this week sparked fears of a wider war in the Middle East, was buried in Qatar following Friday prayers.

Thousands of mourners gathered at Doha’s Imam Abdul Wahhab Mosque, the largest state mosque in Qatar, to bid farewell to the man regarded as the Islamist Palestinian group’s overall leader.

The funeral service, which was attended by Qatari and Arab officials, began at midday with a call to prayer at the mosque.

After the service mourners accompanied Haniyeh’s casket, draped in the Palestinian flag, in a procession. He was later buried in a cemetery in the city of Lusail, north of Doha.

As the caskets of Haniyeh and his bodyguard, who was also killed in the attack on Wednesday, went out of the mosque chants echoed “Rest rest Haniyeh, Hamas will go on.”

Qatari state television, which broadcast the ceremony, reported that the highest security precautions has been taken. It added that the burial ceremony would therefore took place only within the immediate family circle.

“I tell you his blood will be mixed with the blood of the Palestinian martyrs and it will bring victory and Liberation to our nation,” Khalil al-Haya, a senior Hamas official, was seen in a video posted on the movement’s Telegram channel telling Haniyeh’s family.

Haniyeh, and some of his family, had been living in exile in the Gulf Emirate of Qatar for years.

He was killed on Wednesday in an Iranian government guest house in Tehran.

Haniyeh had gone to the Iranian capital for the inauguration of the new Iranian President Masoud Pezeshkian.

Iran and Hamas blame Israel for the brazen attack and have vowed retaliation. Israel has neither confirmed or denied a role in Haniyeh’s death.

Thousands of people already joined a state-organized mourning ceremony in Tehran on Thursday.

Haniyeh and the dead in the Gaza Strip were commemorated in prayers in mosques in the West Bank and East Jerusalem.

In Turkey, prayers for Haniyeh were also held in mosques across the country, as the Turkish state broadcaster TRT reported.

There were also solidarity events in Lebanon. Hundreds of people took to the streets in the capital Beirut to show solidarity with the slain Hamas leader.

Haniyeh had been part of the Islamist terrorist organization for decades.

In the ongoing war with Israel in the Gaza Strip, he had been a key player in negotiations to secure a ceasefire and the exchange of hostages held in Gaza for Palestinian prisoners held in Israeli jails.

The pro-Iranian Hezbollah chief Hassan Nasrallah vowed on Thursday to avenge the recent Israeli assassination of the movement’s top commander, Fuad Shukr, in Beirut, as well as Haniyeh’s killing.

“Our response is coming,” Nasrallah said during the funeral of Shukr, the group’s top military commander and the head its operations in southern Lebanon.