Israel launched an airstrike against Hamas leaders in Qatar on Tuesday, expanding its military actions that have ranged across the Middle East to include the Gulf Arab state where the Palestinian Islamist group has long had its political base.

Qatar, which has acted as a mediator alongside Egypt in talks on a ceasefire in the almost two-year-old war in Gaza, condemned the attack as "cowardly" and called it a flagrant violation of international law.

Two Hamas sources told Reuters that Hamas officials in the ceasefire negotiating team survived the attack, which followed an evacuation order in Gaza City where Israel is waging an offensive to try to destroy the group and its military capabilities in the Gaza Strip.

Israeli officials told Reuters the strike was aimed at top Hamas leaders including Khalil al-Hayya, its exiled Gaza chief and top negotiator.

The attack took place shortly after Hamas' armed wing, the al-Qassam Brigades, claimed responsibility for a shooting that killed six people at a bus stop on the outskirts of Jerusalem on Monday.

The assault is likely to deal a serious, if not fatal, blow to efforts to reach a ceasefire, especially since negotiations took place in the Gulf Arab country Qatar.

The United Arab Emirates, which normalised relations with Israel under the Abraham Accords in 2020, called the Israeli attack on Doha "blatant and cowardly".

Abu Dhabi was already angry over an Israeli minister's plan for annexation in the Israeli-occupied West Bank, saying that was a red line that cannot be crossed.

Regional power Saudi Arabia denounced what it called a "brutal Israeli aggression" against Qatar's sovereignty.

Several blasts were heard in Qatar's Doha, Reuters witnesses said. Plumes of black smoke were billowing from the city's Legtifya petrol station. Next door to the petrol station is a small residential compound that has been guarded by Qatar’s Emiri Guard 24 hours a day since the beginning of the Gaza conflict.

Ambulances and at least 15 police and unmarked government cars thronged the streets around the blast site an hour after the strike.

Here are some of the top Hamas figures killed by Israel and those who remain alive almost two years since the start of the Gaza war, which began when the group attacked communities in southern Israel on October 7, 2023:

DEAD

MOHAMMAD SINWAR

Mohammad Sinwar was a veteran Hamas commander and its overall military chief in Gaza at the time Israel said it killed him in May.

Sinwar had been elevated to Hamas' top ranks after Israel killed his older brother, Yahya Sinwar, a mastermind of the October 7 attacks, in 2024.

YAHYA SINWAR

The Israeli military killed Yahya Sinwar in Gaza in October, 2024, just over a year after the October 7 attacks he helped to plan. Sinwar had been Israel's most wanted enemy at the time, and was widely assumed to be running the war in Gaza. He became Hamas chief after the assassination of Ismail Haniyeh, in Iran in July 2024.

ISMAIL HANIYEH

Haniyeh was assassinated in July 2024 during a visit to Tehran. He had been Hamas leader since 2017. Iran's Revolutionary Guards said he was killed by a short-range projectile. The New York Times, citing unnamed sources, reported that the explosion which killed him was a bomb that was covertly smuggled into the guesthouse where he was staying. Israel's defence minister confirmed in December it had killed him.

MOHAMMED DEIF

Israel's military said Deif, commander of Hamas' military wing, was killed after fighter jets struck in the area of Khan Younis in July 2024. Deif, who had survived seven Israeli assassination attempts, was believed to have been another October 7 mastermind.

MARWAN ISSA

Deputy Hamas military commander Marwan Issa was killed in an Israeli strike in March 2024, the Israeli military said. He had been at the top of Israel's most-wanted list alongside Deif and Sinwar.

SALEH AL-AROURI

Deputy Hamas chief Saleh al-Arouri was killed by an Israeli drone strike on Beirut's southern suburbs in January 2024. He was a founder of Hamas' military wing, the Qassam Brigades.

ALIVE

IZZ AL-DIN AL-HADDAD

Haddad became the most senior Hamas military leader in the Gaza Strip after Mohammad Sinwar's death. Israel believes he is one of the masterminds of October 7, and has identified him among its most wanted. He is believed to be based in northern Gaza, the focal point of a new Israeli offensive.

KHALIL AL-HAYYA

Based in Qatar, Hayya has been widely seen as Hamas' most influential figure abroad since Haniyeh's death. He is part of a five-man leadership council that has led Hamas since Yahya Sinwar's death. Hailing from the Gaza Strip, he has lost several close relatives - including his eldest son - to Israeli strikes.

KHALED MESHAAL

One of Hamas' most recognisable politicians Meshaal, 68, led the group between 2004 and 2017. He became known around the world in 1997 when Israeli agents injected him with poison in Jordan in a botched assassination attempt. He is now based in Qatar, serving on the five-man leadership council.

MOHAMMAD DARWISH

Also based in Qatar, Mohammad Darwish was a little known figure until the Haniyeh assassination, since when he has risen to prominence. He is believed to be the chairman of the Hamas Shoura Council, the highest decision-making body. He is nominally the head of the five-man leadership council.

NIZAR AWADALLAH

Nizar Awadallah, a veteran Hamas leader, was a confidant of the group's co-founder Sheikh Ahmed Yassin, and has taken several key posts within the group including in its armed wing.

Hamas sources said Awadallah led Hamas in Gaza in 2006 in the wake of the group's victory in a parliamentary election. He has made no public appearance or comments since the October 7 attacks, and is believed to have left Gaza before the war began.

ZAHER JABBARIN

Jabbarin is the head of Hamas in the Israeli-occupied West Bank, a role he performs from Qatar. He is the fifth member of the leadership council. He is in charge of the portfolio of Palestinian prisoners and part of the negotiating team.

Israel arrested him in 1993 and he was sentenced to life, before he was freed in 2011 as part of a Hamas-Israel swap deal under which Israel released over 1,000 Palestinians in return for Gilad Shalit, a soldier Hamas captured in 2006.

Born in 1968 in Salfit in the West Bank, he co-founded the first cells of the Hamas armed wing in the West Bank in 1991.