Ahmed was attending a university lecture in Doha when he heard loud bangs: explosions caused by Israeli strikes targeting Hamas, an unprecedented attack that has shaken peace in Qatar and caused tension in the wealthy Gulf region.

"Honestly, no one thought it was an explosion. I thought some workers had dropped something heavy," the 27-year-old Qatari student, who preferred not to give his last name, told AFP.

Shock quickly spread across the wealthy gas-rich emirate after the raids, which hit a compound housing officials of the Palestinian Islamist movement in an upscale neighborhood of Doha on Tuesday. The attack left six people dead.

Just three months after an Iranian attack on a US base in Qatar, this new raid has shattered the image of calm that the Gulf countries pride themselves on, which like to present themselves as an oasis of stability in the heart of a troubled Middle East.

The Israeli operation also raises questions about Qatar's mediation efforts for a ceasefire in Gaza and the security assurances provided by Washington, a key ally of the Gulf states.

In a show of solidarity, UAE President Mohamed bin Zayed Al Nahyan visited Doha on Wednesday, where Saudi Crown Prince Mohammed bin Salman is expected on Thursday.

"Qatar has long benefited from American military protection. From now on, the Gulf will question the credibility of these American security guarantees," analyzes Asli Aydintasbas, researcher at the Brookings Institution, on the X network.

- Economy and security threatened -

Any instability poses a threat to the Gulf economies, which are largely dependent on foreign labor and engaged in diversification towards tourism and investment.

"The entire region will now fear that Israel will attack its enemies without regard for borders or national sovereignty," said Prem Kumar, a former Obama administration official for the Middle East.

Assem, 29, a long-time refugee in Qatar with his family from the Palestinian territories, says he is amazed: "I have lived here in safety for 29 years (...) I am very surprised that in such a short time we have been attacked twice in a country considered very protected."

According to Hamas, none of its senior officials died on Tuesday as they met to discuss a new US proposal for a truce in Gaza.

The attack, however, cost the lives of the deputy and son of Khalil al-Hayya, the Palestinian movement's main negotiator, and three bodyguards, as well as a Qatari security agent.

Doha has hosted several rounds of indirect negotiations between Israel and Hamas and contributed to two brief truces in the Gaza Strip, in partnership with Washington and Cairo, also mediators in the conflict.

While assuring that Doha would continue its mediation efforts, the Qatari Prime Minister affirmed that there were no negotiations planned at this stage in view of the attack.

- "Dig a ditch" -

For Andreas Krieg, a lecturer at King's College London, this is "an attack on the heart of regional mediation" that Washington has failed to prevent.

"This illustrates Trump's inability to enforce the policy he advocated, which was centered on mediation."

A major ally of Washington, Qatar is home to the largest American base in the region and, since 2012, has been the political office of Hamas, with the approval of the United States.

In May, the US president toured the Gulf, collecting promises of colossal investments and a major order from Boeing by Qatar Airways.

Doha even offered Donald Trump a $400 million luxury plane intended to become the new Air Force One.

But these privileged relations did not prevent the Israeli attack.

The US president claimed he had no advance warning, but insisted he had asked his envoy, Steve Witkoff, to alert Doha as soon as he was notified of the attack. But it was already underway.

According to Andreas Krieg, this "will strain US-Qatari relations, which is precisely Israel's goal: to drive a wedge between Doha and Washington."