Israel’s military warned residents of the city of Baalbek in eastern Lebanon to evacuate on Wednesday, two days after a barrage of Israeli airstrikes killed dozens of people in the city and the region around it.

Baalbek, which had a population of roughly 80,000 people before Israel stepped up its attacks on the Lebanese militant group Hezbollah this month, is an important urban center in the Bekaa Valley and is famed for its towering Roman ruins. It is also well known as a city where Hezbollah holds sway. But unlike other places where the group enjoys support, Baalbek has largely been spared Israeli bombardment.

In a statement posted online on Wednesday, Avichay Adraee, the Israeli military’s Arabic-language spokesman, signaled that this would no longer be the case. He posted a map showing the city and two neighboring towns, Ain Bourday and Douris, as part of a danger zone marked in red, with three evacuation routes authorized by the Israeli military.

“The I.D.F. will act forcefully against Hezbollah interests within your city and villages and does not intend to harm you,” Mr. Adraee said. “For your safety, you must evacuate your homes immediately and move outside the city and villages.”

The evacuation warning comes two days after Israeli airstrikes killed at least 60 people in the Bekaa district, which includes the city and its rural hinterland, Lebanese officials said. Lebanon’s health ministry said at least 58 others were injured in the attacks.

As people in Baalbek received the evacuation warnings by text message late Wednesday morning, a sense of alarm seized the streets of the city, according to Ibrahim Bayan, a deputy to the mayor in Baalbek.

“People are panicking,” Mr. Bayan said. “They are running around and bumping into each other, like chickens with their heads cut off. They have no idea what to do, where to go.”

Within minutes, the roads filled with residents who threw their valuables into plastic bags, locked their houses and pulled metal grates over their shop doors, he said. As people crammed into cars, they shouted to each other to determine the safest way to leave the city.

Fighting between Israeli forces and Hezbollah continued elsewhere in Lebanon. On Wednesday, the Israeli military said it had struck more than 100 sites across the country in the previous 24 hours, including a rocket launch site used in a deadly strike on the Israeli town of Ma’alot-Tarshiha on Tuesday.

Hezbollah said its forces had battled Israeli troops in recent days near the border town of Kfar Kila and the mountain town of Khiam, which is well known in Lebanon as the former site of a prison camp run by allies of Israel during its two-decade occupation of southern Lebanon. The claims could not be independently verified.

The camp was turned into a museum by the Lebanese government after Israel withdrew in 2000, although it was later destroyed by an Israeli airstrike during the 2006 war in Lebanon.

Jacob Roubai contributed reporting.