Canada's embassy in Cairo was closed on Monday until further notice because of security concerns, an official answering its emergency telephone line said, the second diplomatic mission to shut its doors this week.
A message on the embassy's website read: "The ability to provide consular services may occasionally be limited for short periods due to unsettled security conditions." It gave no more details.
The British Embassy in Cairo closed to the public on Sunday, also citing security concerns. A notice on its website on Monday said its services remained suspended.
Egypt is battling an Islamist insurgency largely centred around the Sinai Peninsula, a strategic area near the border with Israel, Gaza and the Suez Canal.
Insurgent attacks have mostly targeted Egyptian police and soldiers, killing hundreds in the past year, but Egypt's most dangerous militant group, Sinai Province, said last week it was behind the killing of an American oil engineer in the western desert in August.
Smaller bombs also regularly explode in Cairo and the Nile Delta, usually causing limited injuries.
One security source told Reuters on Sunday it was not yet clear what threats had prompted the British embassy to close its doors. But another source, who spoke on condition of anonymity, said a suspected militant who was recently detained by Egyptian authorities had confessed to plans to target foreign embassies.
The U.S. embassy was open as usual, a spokesman said. It released a statement on Dec. 4 warning staff not to stray too far from their homes.
Australia also updated its travel advice to Egypt on Dec. 6, because of reports early in the month indicating that "terrorists may be planning attacks against tourist sites, government ministries and embassies in Cairo".
"We continue to advise against all travel to the governorate of North Sinai. We continue to advise Australians to reconsider their need to travel elsewhere in Egypt due to ongoing political tension and the threat of terrorist attack," it said
Meanwhile, the Foreign Ministry spokesperson Badr Abdel Aaty told LTC satellite channel on Sunday that the security situation in Egypt is continuously improving. "There is no country immune from terrorist threats”, he added.
