“Hamas is distinguished by its high institutionalism and firm Shura Council, which was reflected in the facts and events during the past decades that witnessed the martyrdom of a number of its leaders, as it was quick to choose alternatives for them according to the movement’s regulations and systems,” Hamas said in a statement.

The statement added that the movement's executive institutions and Shura, the main consultative body, are continuing their work and that the group will announce the results of its consultations once they are completed

Sources in Hamas told Asharq Al-Awsat newspaper that the group has temporarily frozen ceasefire talks in the Gaza Strip.

They said a decision was taken to suspend contacts until “choosing a successor to the head of the politburo, Ismail Haniyeh,” who was assassinated by Israel in Tehran last week.

The sources added that choosing Haniyeh’s successor will be accomplished within the next few days.

Hamas has a history of swift and smooth replacement of leaders killed in Israeli airstrikes.

Haniyeh’s assassination in the Iranian capital early Wednesday came at a time when Hamas is under extreme pressure since the war in Gaza started nearly 10 months ago.

Haniyeh headed the group’s political bureau until his death. His deputy was Saleh Arouri, who was killed in an Israeli strike in Beirut in January and would have been the automatic replacement. Arouri’s post has remained empty since his death.

The group’s Shura Council is expected to meet soon, likely after Haniyeh’s funeral in Qatar, to name a new successor. The council’s membership is kept secret but represents regional chapters of the group in Gaza, the West Bank, and the diaspora along with those imprisoned.

A full leadership meeting may be complicated by their inability to convene. Many of the group’s nearly 60 members are in Gaza, according to an AP report.

Hani Al-Masri, an expert on Palestinian organizations, said a consensus candidate may be named before the Shura can convene, with a formal election to be held by the council later. The elections were already delayed this year because of the war.

One of Haniyeh’s deputies was Zaher Jabarin, who has been described as the group’s chief executive officer because of his important role in managing the group’s finances and his good offices with Iran and other backers.

A-Masri said the choice is likely between Khaled Mashaal, another Haniyeh deputy and former leader of the group, and Khalil Al-Hayya, a powerful figure within Hamas who was close to Haniyeh.

“It will not be easy,” said Al-Masri, head of the Palestinian Centre for Policy Research and Strategic Studies.

Mashaal has political and diplomatic experience, but his relations with Iran, Syria, and Hezbollah have soured over his support for Arab protests in 2011. When he was in Lebanon in 2021, Hezbollah leaders reportedly refused to meet with him.

However, Mashaal has good relations with Turkey and Qatar, where the group is based, and is considered a more moderate figure who headed the group until 2017. Palestinian leader Mahmoud Abbas called him on Saturday to offer his condolences for the killing of Haniyeh.

Yahya Sinwar, the powerful Hamas figure leading the war in Gaza, is at the opposite end of that spectrum and unlikely to support Mashaal’s leadership.

Al-Hayya, who is Sinwar’s deputy, is a prominent leader living originally in Gaza, with important international connections and good relations with the military wing and with Iran, Qatar, Egypt, and Turkey. He was the first leader to speak after Haniyeh's assassination.

After years of cold relations with the Iran-led “axis of resistance” over Hamas’ backing of the opposition against Syrian President Bashar Al-Assad during Syria’s conflict that began in March 2011, Hamas started to mend its relations with Iran and reconciled with Al-Assad.

In 2022, Al-Hayya headed a delegation to Syria and met with President Al-Assad.

“He is like Haniyeh, who was balanced and flexible, and both sides didn’t see his leadership as problematic,” Al-Masri said.

A third possible contender, said Al-Masri, is Nizar Abu Ramadan, who had challenged Sinwar for the role of Gaza chief and is considered close to Mashaal. Moussa Abu Marzouk, Mashaal’s deputy, is another potential candidate.