Israel faced warnings on Wednesday of a wider regional war after a leading Hamas official was killed by a drone strike in Lebanon.
Saleh al-Arouri, 57, was the most senior figure from the Palestinian terror group to have been killed since Hamas attacked Israel on October 7, igniting a war in Gaza that has left thousands dead.
He was killed along with two other Hamas commanders and four other people in a drone strike on a Beirut apartment block, according to officials from the group, the Lebanese government and Lebanon's powerful Hezbollah militia.
Hezbollah leader Sayyed Hassan Nasrallah has vowed to hit back against any Israeli targeting of Palestinian officials in Lebanon, and the group has been exchanging near-daily fire with Israel across Lebanon's southern border since the Gaza war erupted.
Hezbollah called the Beirut strike "a serious attack on Lebanon, its people, its security, sovereignty and resistance", adding: "We affirm that this crime will never pass without response and punishment."
Arouri was deputy to the Hamas supreme political leader, Ismail Haniyeh, and headed the group in the West Bank.
He was also a key liaison with Hezbollah, and was said to be heavily involved in negotiations mediated by Qatar and Egypt aimed at securing a ceasefire in Gaza with the release of Hamas-held Israeli hostages.
Hundreds of Palestinians took to the streets of Ramallah and other towns in the West Bank to demand revenge for Arouri's killing.
Iran, which backs Hezbollah and Hamas, said the assassination would "undoubtedly ignite another surge in the veins of resistance... not only in Palestine but also in the region and among all freedom-seekers worldwide".
Israel's government never comments on strikes against its enemies abroad. But Prime Minister Benjamin Netanyahu had threatened to kill Arouri before the Hamas-Israel war began.
Israel had indicated that another assassination campaign was in the works after October 7, modelled on the years-long effort to eliminate Palestinians blamed for the massacre of Israeli athletes at the 1972 Munich Olympics.
Military spokesman Rear Admiral Daniel Hagari did not directly mention Arouri's death but said: "We are focused and remain focused on fighting against Hamas."
However, a US official agreed that Israel was responsible for the Beirut attack. And right-wing Israeli MP Danny Danon tweeted his congratulations to Israeli security and intelligence forces, vowing that the country would "settle accounts" with those behind the October 7 bloodshed.
Arouri and the others were killed on Tuesday night in the attack on the city's southern suburbs of Dahiyeh. Among the dead were two leaders of Hamas' armed wing Al Qassam Brigades, Samir Findi Abu Amer and Azzam Al-Aqraa Abu Amma.
Lebanon's caretaker prime minister Najib Mikati condemned the drone blast as a "new Israeli crime" and said it was an attempt to pull Lebanon into war.
The Lebanese government said it would complain to the UN Security Council about what it called "Israeli violations of Lebanese sovereignty".
It came on the same day Turkish authorities detained 34 people suspected of links to Israel's Mossad intelligence service and of targeting Palestinians living in Turkey.
Last month, Turkish officials warned Israel of "serious consequences" if it tried to hunt down members of Hamas living outside Palestinian territories, including in Turkey.
Turkey, unlike most of its Western allies and some Arab nations, does not classify Hamas as a terrorist organisation and has issued angry denunciations of Israel for the Gaza war.
Earlier, Interior Minister Ali Yerlikaya said the suspects were detained in 57 locations, including in Istanbul, as part of an operation dubbed "Operation Mole", adding they were believed to be aiming to identify, monitor, assault and kidnap foreign nationals living in Turkey.
