The Jordanian Tourism Ministry on Wednesday warned Israeli visitors not to wear outwardly Jewish garb while visiting the Hashemite Kingdom and to avoid performing Jewish rituals during their stay.

According to a copy of a ministry memo issued at the end of November, Amman instructed Jordanian tour operators to inform their Israeli counterparts to advise Israeli visitors not to wear “Jewish dress” or perform “religious rituals in public places” so as to prevent an unfriendly reaction by Jordanian citizens.

The Jordan Society of Tourism and Travel Agents forwarded on the imperative to Jordanian tour operators, one of whom forwarded a copy to The Times of Israel.

The memo did not specify what constituted Jewish clothing.

The Jordanian Tourism Ministry was not available for comment on the story.

Israeli tour operators contacted by The Times of Israel had not been notified of any such directives. Kfir Schwartz, director of Ahalan Olympus, a tour company in Israel that organizes trips to Jordan, said that such advisories are “not something new” but have never been formal.

Despite the liberal atmosphere in Jordan, he said, Israelis and Jews are typically advised not to wear outwardly Jewish clothes or symbols, and occasionally are met with trouble from Jordanian authorities when crossing the border.

Earlier this year, six Israeli tourists were assaulted in a market in southern Jordan after vendors were angered by their traditional Jewish skullcaps.

The six men and women arrived at a market in the town of Rabba, 100 kilometers (62 miles) south of the capital Amman, when one of the vendors identified the tourists as Israeli due to mens’ skullcaps, which “provoked the sensibilities of the vendors,” independent daily Al-Arab Al-Yawm reported.