Yesterday morning, two deep, reverberating booms sounded across Beirut.

The three other women in my co-work leapt up from their desks and dashed to the window in panic. Peering down from our tall office block, one woman scanned the boxy buildings below for any signs of smoke that might indicate a bomb.

“Just sonic booms,” she said, turning back to us after a few seconds, the alarm gone from her face. It was a sign that Israeli jets were circling above the city, travelling faster than the speed of sound.

Despite one revealing moment of panic, many Lebanese, hardened by decades of conflict and threat, are defiant.

The country’s residents are braced for war after two assassinations, of a senior Hezbollah commander, Fuad Shukr, in Beirut and Hamas’s political head, Ismail Haniyeh, in Tehran. Hezbollah and Iran have promised a “serious” response.

However, at the weekend, many of the city’s residents flocked to the coast, sunning themselves on beaches that foreign diplomats are scouting out as possible evacuation routes.

Meanwhile, my phone pinged with updates from embassies, urging their citizens to leave the country.

“Tensions are high, and the situation could deteriorate rapidly,” Foreign Secretary David Lammy announced on Saturday. “My message to British nationals there is clear—leave now.”