Canada on Monday joined Britain in closing its embassy in Cairo to the public for security reasons, with neither country providing details about any specific threat.
The move comes amid increasing attacks by Islamist militants in Egypt and calls from the extremist Islamic State (IS) group for attacks on Western targets.
The Canadian embassy said in a statement that it would be closed "due to security reasons" on Monday, with a separate email to Canadian citizens in Egypt saying this would be "until further notice".
The British embassy also remained closed after shutting its public services on Sunday.
British Ambassador John Casson said the decision had been taken "to ensure the security of the embassy and our staff".
"We are working to restore full services as quickly as possible," he said.
Egyptian foreign ministry spokesman Badr Abdelatty said he was unaware "of any specific threat" to the missions.
"They informed us that it is a precautionary action... but we are dealing with the matter seriously," he told AFP.
"Our security apparatus is applying maximum security measures on the ground and we hope that the embassies do not exaggerate the matter out of context."
Cairo security chief Ali al-Demerdash also said he was unaware of any specific threat to the two embassies.
"No one has informed us of any security threat. We boosted security around embassies in Cairo and vital institutions a long time ago," he told AFP.
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Both Britain and Canada previously issued warnings to their citizens against travelling to restive areas including parts of the Sinai Peninsula, where the Ansar Beit al-Maqdis militant group has pledged allegiance to IS.
The American embassy, which like the two others is in central Cairo, remained open Monday.
Australia updated its travel warning to nationals on Saturday, citing the "ongoing political situation and the threat of terrorist attack" in Egypt.
"Terrorist attacks could occur at anytime, anywhere in Egypt, including in tourist areas," the Department of Foreign Affairs and Trade website said, specifically banning travel to the insurgent bastion of North Sinai.
Canberra's embassy in Cairo remained open for public services on Monday.
Foreign missions have stepped up security measures since last year's ouster of Islamist president Mohamed Morsi prompted a rise in militant attacks on the security forces.
No foreign missions or interests have been directly targeted.
Most attacks have been in the Sinai, but Cairo and other cities have also experienced several deadly blasts.
IS, which has captured swathes of territory in Iraq and Syria, has called on affiliate groups to target foreign nationals and interests, especially citizens of states belonging to a US-led coalition fighting the jihadists.
Both Britain and Canada have joined the coalition, flying missions against IS targets in Iraq.