An Egyptian military bulldozer dismantles Cairo's Al-Nahda square protest camp after Egyptian security forces dispersed supporters of Egypt's ousted president Mohamed Morsi in two huge camps in the Egyptian capital on August 14, 2013. UPI/Karem Ahmed

GENEVA, Switzerland, Jan. 31 (UPI) -- Rupert Colville, a spokesman for the U.N. High Commissioner for Human Rights, said Friday he was frustrated by reports of an Egyptian crackdown on the media.

"We are extremely concerned about the increasingly severe clampdown and physical attacks on media in Egypt, which is hampering their ability to operate freely," he said in a statement.

Colville said his office was monitoring reports that journalists covering last week's anniversary of the 2011 revolution were injured by live fire and rubber bullets. He said pro- and anti-government forces may be to blame for the shootings.

He added Wednesday's announcement that 20 journalists working for al-Jazeera could face charges related to terrorism was a grave concern.

Ahram Online, an Egyptian news website, reported Monday more than 50 of the 64 confirmed casualties reported from last week's demonstrations died as a result of gunshot wounds.

The British government issued a travel advisory for Egypt Friday warning of the possibility of further unrest.

"From Feb. 1 for approximately 2 months there will be several anniversaries in Egypt which are expected to prompt protests, some of which could turn violent," the warning said.

The political climate and national security situation in Egypt has been unstable since a 2011 uprising prompted longtime President Hosni Mubarak to stand down.