The US and Britain on Thursday lodged high-level diplomatic protests with the Zimbabwean authorities after envoys from both countries were detained and intimidated by police outside the capital Harare.

In an incident which underscores the growing atmosphere of violence inside Zimbabwe ahead of this month’s presidential election run-off, Zimbawean police detained a convoy of three vehicles – two US and one British – in the town of Bindura, some 80km north of Harare.