The burial ceremony for Hamas’s political leader, Ismail Haniyeh – who was assassinated in Iran on Wednesday – is under way in Qatar.

Funeral prayers for Haniyeh will take place at the Imam Muhammed bin Abdul Wahhab mosque – the largest in Qatar – before he is buried at a cemetery in Lusail, a city north of Doha.

Prominent figures in the Hamas movement – including his predecessor as leader, Khaled Meshaal – stood on the tarmac at Doha airport as the plane carrying Haniyeh’s coffin landed from Iran on Thursday afternoon.

Haniyeh was killed during a visit to Iran’s capital. Iran and its allies have blamed Israel, though Israel has not claimed responsibility for his death.

Hamas said that “Arab and Islamic leaders” and those involved with other Palestinian factions would attend, as well as members of the public.

Turkey and Pakistan announced a day of mourning on Friday in honour of Haniyeh, while Hamas has called for “roaring anger marches… from every mosque” to take place after Friday prayers to protest Haniyeh’s killing.

At a separate funeral ceremony for Haniyeh which took place in Tehran on Thursday, Iran’s supreme leader, Ayatollah Ali Khamenei, vowed that Israel would suffer a “harsh punishment” for the killing.

Haniyeh had been based in Doha since about 2019. The Hamas political office moved to the Qatari capital in 2012, following the closure of its previous office in Damascus, Syria.

Haniyeh had played a key role in talks over a potential ceasefire deal, working with mediators in Qatar, where the majority of the ceasefire negotiations took place.

The heads of the CIA, Mossad and the intelligence services of Egypt and Qatar had attended the talks in Doha.

Haniyeh’s burial caps a week of simmering tensions in the Middle East, which began with the deaths of 12 children and teenagers after a rocket fell on Israeli-occupied Golan heights.

Israel accused Hezbollah and vowed “severe” retaliation, though Hezbollah denied it was at fault.

Days later, senior Hezbollah commander Fuad Shukr was killed by a targeted Israeli airstrike in Beirut. Four others, including two children, were also killed.

Hours after that, Ismael Haniyeh was assassinated in Iran. Earlier that day, he had attended the inauguration of Iran’s new president, Masoud Pezeshkian.

Israel has not claimed responsibility for the assassination, but Israeli prime minister Benjamin Netanyahu has said Israel delivered “crushing blows” to Iran’s proxy groups in recent days.

A senior Hamas official told the BBC the killing took place in the same building where Haniyeh had stayed during previous visits to Iran. Three Hamas leaders and a number of guards were with him in the same building, they said.

The circumstances around his death remain unclear.

The killing of Haniyeh left the leadership of Hamas in “a state of shock”, top Hamas officials told the BBC.

Khalil al-Hayya, a senior Hamas official, told a news conference that a missile hit Haniyeh “directly”, citing witnesses who were with him.

But a conflicting report in US newspaper the New York Times, which cites seven officials, suggests Haniyeh was killed by a bomb that had been smuggled into the Iranian building he was staying in.

The BBC has not been able to verify either of these claims.