The Foreign Office has updated its advice to warn tourists about protests in Egypt and Brazil.
A series of large protests are planned for Cairo, Alexandria and other Egyptian cities from today.
Tourists are asked to exercise caution at potentially sensitive locations such as government buildings, police stations, security directorates, political party offices, military barracks, the vicinity of Tahrir Square, the presidential palace and the Mokkatam area in Cairo.
The FCO website adds: " Do not attempt to cross roadblocks erected by demonstrators, or the security forces. Monitor travel advice updates and the local media for further information."
The protestors want Islamist President Morsi to step down ahead of the anniversary of his coming to power on June 30.
In Brazil, there have been a number of protests which, while generally peaceful, have included violent incidents and injuries.
The protests began over a week ago against increased transport fares but have escalated into a nationwide movement about a wide range of issues, from corruption and poor public services to the cost of staging international football tournaments.
The Foreign Office says further protests are planned across cities throughout the country including Recife and Brasilia on June 26.
It says there will be Confederation Cup semi-final matches at 4pm on June 26 in Belo Horizonte and June 27 in Fortaleza which could attract further protests.
