CAIRO — It seemed harmless enough: Two celebrity crooners, Mohamed Ramadan and Omer Adam, taking a photo with each other in a Dubai restaurant. The picture, posted online over the weekend, went viral. Then came the blowback.

Ramadan is Egyptian. And Adam is Israeli.

That was enough to generate a massive and ongoing uproar on social and traditional media, stretching across the Middle East. It underscores how even in a time of diplomatic normalization with Israel, historic tensions with the Jewish state continue to tug at the hearts of many Arabs.

“Whether he knew or not, what happened is a confirmation that cultural and public normalization is a crime that should be punished,” tweeted Egyptian actor Nabil al-Halafawy, known for a movie role as an Egyptian soldier who defeated the Israeli army.

The outcry comes amid recent normalization agreements, orchestrated by the Trump administration and dubbed the Abraham accords, between Israel and, separately, the United Arab Emirates, Bahrain and Sudan. But on the streets of many Arab capitals, especially Cairo, many denizens view any relationship with Israelis as forbidden and any normalization with the Jewish state as a betrayal of the Palestinian cause.

This week, Ramadan was banned from acting and singing by Egypt’s Theatrical Professions Syndicate pending an investigation scheduled for next month. A journalists union blasted Ramadan — and urged its members to boycott him — for violating a code that prevents members of the country’s artists syndicate from interacting with Israelis. And an Egyptian lawyer filed a lawsuit against Ramadan for allegedly tarnishing the country’s image.

Even staunch allies of Egyptian President Abdel Fatah al-Sissi condemned Ramadan, even though Egypt was the first country to sign a peace treaty with Israel in 1979 and today closely works with Israel on regional security matters. Ahmed Moussa, a well-known television host and Sissi loyalist, termed the photo “a full-fledged crime” and called for harsher measures to prevent any more Egyptian artists from interacting with Israelis.

By Wednesday, Ramadan had changed his Facebook cover page to a photo of the Palestinian flag and claimed he was unaware that Adam was an Israeli. Ramadan posted a photo of himself in patriotic military attire — Egypt fought four wars against Israel from 1948 to 1973 — and wrote: “I did not know his nationality and had I known I would have refused to have my picture taken.”

The photo was apparently taken this month at a restaurant in Dubai. In addition to Adam, Ramadan was also photographed with Israeli “Big Brother” reality TV star Elad Tsapani and with Arab-Israeli soccer player Dia Saba, who signed with the UAE soccer club al-Nasr in September.

Over the weekend, an Emirati journalist posted the photo of Ramadan, his arm around Adam, with the caption: “The most famous artist in Egypt with the most famous artist in Israel. Dubai brings us together.”

The photo, along with its symbolism, was soon picked up by both Arabs and Israelis.

Avichay Adraee, an Israel Defense Forces spokesman, tweeted in Arabic: “How beautiful are art, music and peace! The great Egyptian artist Mohamed Ramadan with the brilliant Israeli artist Omer Adam in Dubai!!”

The controversy was met mostly with surprise by Israelis on Wednesday. Many expressed sympathy for Ramadan’s expected professional and legal troubles and questioned why the photo inspired such harsh reactions against the Egyptian singer.

“In Israel and in the Arab world, people are asking why all this fire is being directed at Mohamed Ramadan, when there are a lot of Arab politicians who have already been photographed with Israelis and Arab countries who have signed agreements with Israel,” said Moran Tal, an Arabic teacher in central Israel.

“Not sure [Ramadan] should return to Cairo soon. The excuse that he ‘didn’t know’ is beginning to dissolve,” Roi Kais, an Arab affairs correspondent for the Kan TV channel, tweeted with a photo of Ramadan and Saba.

Adam did not immediately respond for comment.

By Wednesday, the controversy had grown. Videos of Ramadan dancing to an Israeli folk song and more photos of him with Israelis were crisscrossing the social media universe.

 In Egypt, the outrage has now taken on a nationalistic tone, accompanied by demands that any artist seeking to “culturally normalize” with Israel be boycotted. Few Egyptians appear to believe Ramadan’s claim that he was unaware he was with Israelis.

“The problem has surpassed the photo,” Ashraf Zaki, head of the Theatrical Professions Syndicate, told the MBC Masr television network. “Yesterday it was only about the photos, but today there are videos and Israeli songs, too.” Some people view what Ramadan did as “normalizing with Israel,” he said.

 Zaki added that Ramadan would be “summoned” when he returns from Dubai and would be asked to make a statement explaining what happened. The union, Zaki added, has reprimanded members in the past for interactions with Israel.

Others, though, are seeking harsher measures against Ramadan.

Hussein Abdulghany, a prominent media personality, said Ramadan needs to show through a new video that he “clearly denounces normalization and clarify in patriotic terms who put him in this shameful fix.” If he doesn’t abide by “artistic and cultural boycotting of the enemy,” the union should suspend Ramadan, Abdulghany added.

One organization critical of Israel, known as the boycott, divestment and sanctions (BDS) movement, called for fans to keep boycotting Ramadan, production companies to terminate their contracts with him, and cinemas and concert organizers to ban his films and songs.

On Wednesday, Ramadan’s Facebook page was filled with unforgiving comments.

“You are a shame to the army uniform you are wearing,” wrote one person.

“Be a man, Ramadan,” wrote another. “Admit that you knew and apologize. Say that you did not evaluate this move well at first and deal with the consequences.”

Rubin reported from Tel Aviv.