Zimbabwe's human rights commission is accusing the ruling party of denying opposition supporters access to government-funded food aid in some districts ravaged by drought.

Parts of southern Africa are suffering the worst drought in more than three decades. Zimbabwe's government says 4 million people, or close to a third of the population, need food aid.

The constitutionally mandated commission on Wednesday said investigations showed "there was indeed discrimination and exclusion of certain citizens in the distribution of food aid."

The commission says ruling ZANU-PF party members were the major perpetrators in the violations in recent months.

The commission says opposition supporters were "told openly that those affiliated to the opposition would never get food aid."

The government has been distributing food aid separately from international organizations.