Scuffles erupted as police arrested the ZCTU leaders after they addressed a crowd outside the unions’ headquarters in the capital.
Before his arrest, a defiant Mutasa told journalists: “We are demonstrating peacefully against hardships. We are here to make the authorities know that Zimbabweans are suffering.”
Large numbers of police were on duty in Harare armed with truncheons, guns and teargas canisters while water cannon trucks were parked on some streets.
Zimbabwe’s moribund economy has hit new lows in recent days with shops struggling to stock shelves, medicine running out and long queues outside petrol stations.
The local “bond note” currency, which in theory has the same value as the US dollar, has been in freefall in recent weeks, raising fears of a return to the hyper-inflation that wrecked national finances in 2009.
President Emmerson Mnangagwa, who took power last year after Robert Mugabe was ousted by the military, has vowed to ensure essential daily goods are available.