Violence in Egypt escalated following the July 3 military ouster of President Mohamed Morsi, who remains in military custody. More than 80 people were killed last week in Egypt during confrontations between protesters and national security forces.
British Foreign Secretary William Hague expressed concern about the violence Thursday during a phone conversation with acting Vice President Mohamed ElBaradei. The British government said Friday it was reminding its citizens of the ongoing political violence.
"There are likely to be further large demonstrations with a high risk of violence in the following days," the warning said.
U.S. Secretary of State John Kerry told Pakistani broadcaster Geo TV the military was called on to intervene in Egypt to prevent the country from descending into chaos.
"In effect, they were restoring democracy," he said Thursday.
The Muslim Brotherhood, the Islamic organization from which Morsi hails, criticized Kerry's statements as "very alarming."
The Brotherhood says Morsi's ouster was a coup, though Kerry responded it was not a military takeover "to the best of our judgment so far."