Israel launched an unprecedented airstrike in the Qatari capital of Doha on Tuesday, targeting a building housing senior Hamas officials in what Israeli authorities described as an attempt to assassinate leaders of the group.

Five members of Hamas and a Qatari security officer were killed during the strike, while key members of the negotiating team survived.

The attack occurred while its delegation was discussing a new U.S. proposal presented by U.S. President Donald Trump, Hamas said, accusing Israel of attempting to sabotage international mediation.

The group condemned the strike as "an assault on the sovereignty of Qatar, which, along with Egypt, has played a central role in ceasefire and prisoner exchange mediation." It held Washington "jointly responsible due to its continued support for Israel."

The attack drew swift condemnation from Qatar, a key mediator in the conflict that hosts Hamas's political bureau. The Qatari Foreign Ministry condemned the strike as a "serious threat to the security of Qatari citizens and residents" and a violation of its sovereignty, announcing that an investigation was underway.

Hussein al-Sheikh, a senior Palestinian official, echoed the sentiment, denouncing the assault as a "serious violation of international law."

Qatar has denied being informed in advance of the Israeli strike, which is believed to be the first of its kind carried out by Israel in the country.

Iranian Foreign Ministry spokesman Esmaeil Baghaei described Israel's action as "extremely dangerous, criminal," in "flagrant violation of all international laws and regulations, Qatar's national sovereignty and territorial integrity, and an attack on Palestinian negotiators."

"We are closely examining the events that have occurred. However, in any case, from the perspective of international law, all international law regulations have been violated," he added.

Tunisia on Wednesday condemned in the strongest terms the "treacherous and vicious attack" committed by Israel in a flagrant violation of all international laws and covenants.

According to a statement issued by the Tunisian Foreign Ministry on its Facebook page, Tunisia expressed its full solidarity and support for the brotherly state of Qatar and its efforts to defend its sanctity, sovereignty, national security, territorial integrity and citizens, and expressed its sincere condolences to the families of the victims of this attack.

British Prime Minister Keir Starmer condemned the attack in a readout on social platform X.

"I condemn Israel's strikes on Doha, which violate Qatar's sovereignty and risk further escalation across the region," said Starmer. "The priority must be an immediate ceasefire, the release of hostages, and a huge surge in aid into Gaza."

German Foreign Minister Johann Wadephul called Israel's attack "unacceptable" and warned that it jeopardizes the negotiations for the release of hostages held by Hamas.

The Slovenian Ministry of Foreign and European Affairs said on social media that "Slovenia strongly condemns the attack on the sovereignty and territorial integrity of Qatar," expressing solidarity with Qatar, calling it a key mediator for a ceasefire in Gaza.

Israeli Prime Minister Benjamin Netanyahu called it "a wholly independent Israeli operation." "Israel initiated it, Israel conducted it, and Israel takes full responsibility," he said in a statement released by his office on Tuesday after the attack.

White House press secretary Karoline Leavitt told reporters later in the day that the Trump administration was informed by the U.S. military that Israel was striking Hamas targets, "which very unfortunately, was located in a section of Doha, the capital of Qatar."

Leavitt said that Trump "immediately directed Special Envoy Steve Witkoff to inform Qatar of the impending attack, which he did."

However, Qatar denied having prior knowledge, calling such claims "baseless." "The call from a U.S. official came during the sound of explosions caused by the Israeli attack in Doha," Foreign Ministry spokesperson Majed bin Mohammed Al Ansari said in a post on X. The ministry announced the suspension of ongoing negotiations.

UN Secretary-General Antonio Guterres condemned the strike as a "flagrant violation" of Qatar's sovereignty. "We are just learning about the Israeli attacks in Qatar, a country that has been playing a very positive role to achieve a ceasefire and the release of all hostages," he told reporters in New York.

"I condemn this flagrant violation of the sovereignty and territorial integrity of Qatar. All parties must work towards achieving a permanent ceasefire, not destroying it," he said.

Other countries and organizations, including Norway, Jordan, Türkiye, and the Arab League, also condemned the Israeli attack.