The army has insisted that president Robert Mugabe, who has been in power since 1980 is safe, but an army spokesman announced on state TV that it was targeting people close to the president.
In a statement on its website, the FCO said: “Due to the uncertain political situation in Harare, including reports of unusual military activity, we recommend British nationals currently in Harare to remain safely at home or in their accommodation until the situation becomes clearer.”
It also urged Britons to “avoid political activity, or activities which could be considered political, including political discussions in public places and criticism of the President.”
It added: “You should avoid all demonstrations and rallies. The authorities have sometimes used force to suppress demonstrations”.