Egypt’s foreign ministry sharply criticized the U.S. Embassy in Cairo for advising citizens to avoid large gatherings in the capital until Sunday, calling the move “unjustifiable”.

The embassy’s message warned against being in public spaces, near diplomatic missions, government buildings, and transport hubs. It cited “potential security concerns” but did not specify what they were.

“The foreign ministry spokesman has conveyed his annoyance at the warning released by the United States embassy in Cairo to Americans,” the ministry said in a statement. “(This) raises questions over the reasons this statement was released in such a way.”

The ministry said it contacted the embassy over the warning and that it was told there were no specific reasons or threats behind the move. The ministry quoted the embassy as telling it that the warning was a routine measure taken every time there is a long weekend and thus more crowding in public areas.

Thursday was a public holiday in Egypt in celebration of Armed Forces Day. The Egyptian weekend is Friday and Saturday.

The foreign ministry said it expressed dismay to the embassy because such “unjustifiable warnings” could have negative effects especially on the economy.

Egypt is battling an insurgency largely concentrated in the Sinai Peninsula that which gained pace after its military ousted President Mohamed Mursi in 2013 after mass protests against his rule.

The insurgency, mounted by Daesh’s Egyptian branch Sinai Province, has killed hundreds of soldiers and police and begun to attack Western targets within the country. There have been occasional attacks in Cairo and other cities.

The attacks have dented the recovery of tourism after a 2011 uprising drove away tourists, a major source of hard currency. Import-dependent Egypt is facing a dollar shortage that has stifled business activity and hit confidence in the economy.

Meanwhile, a new Egyptian militant group, the Hasam Movement, on Saturday claimed responsibility for the killing of a policeman in the country’s north.

Gunmen shot Gamal al-Deeb, a policeman working with the Homeland Security agency, eight times outside his home in the northern Beheira province shortly after midnight, the interior ministry said. He died of a bullet to the head.

It accused Deeb of killing, kidnapping, and torturing innocents, including children. The group posted photos it said were of Deeb’s house, car, and a coffee shop he frequented.

Hasam, the Arabic word for decisiveness, has claimed five other attacks since July, including the attempted assassination of a senior prosecutor via car bomb and the failed shooting of Egypt’s former top Muslim cleric. The group also killed a senior police chief earlier this year.