Church leaders and opposition politicians have accused the Zimbabwean government of foot-dragging in the search for an activist who has been missing for four months.

Religious and opposition leaders addressed hundreds of people at a prayer rally for activist Itai Dzamara on Saturday in the capital Harare.

Dzamara's lawyers said they suspect he was abducted by state agents on March 9. Before he went missing, the activist led the Occupy Africa Unity Square movement, staging a sit-in at the popular square in the city that began in October last year to call for President Robert Mugabe's resignation and democratic reforms.

A high court judge ruled that state security agents must find Dzamara, forcing them to act.

Police have dismissed allegations of delay tactics, saying they are investigating Dzamara's disappearance.