President Robert Mugabe has thrown his weight behind militias waging a campaign of intimidation in rural areas where the opposition has made inroads intensifying concerns that a presidential run-off will be scarred by state-sponsored violence.

Gangs of self-styled veterans of the war of independence surrounded six farms in the central Zimbabwean area of Masvingo, on Saturday and twelve farms in the northern area of Mashonaland Central on Sunday, forcing several of the farmers to flee.