The US Embassy in Cairo advised its citizens and employees to limit their movement to the proximity of their neighbourhoods amid calls for demonstrations by supporters of deposed president Mohamed Morsi ahead of his trial on Monday.
In an official statement on Thursday, the embassy warned its citizens against loitering near large gatherings.
"Even demonstrations or events intended to be peaceful can turn confrontational and possibly escalate into violence," the statement read, adding that US citizens should stay tuned to local news for updates.
Meanwhile, Egypt's army has tightened security around Cairo, barricading squares known to be frequent protests sites, to prevent marches from entering them.
The National Alliance to Support Legitimacy, an Islamist coalition backing Morsi, called for the Friday protests under the slogan "President's Perseverance Day".
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