The southern African nation has experienced an acute shortage of dollars that has hampered imports of fuel and drugs and caused a spike in prices.
Zimbabweans accuse President Emmerson Mnangagwa of failing to live up to pre-election pledges to kick-start growth and to have a clean break from the 37-year rule of Robert Mugabe, who was forced out in a de facto coup in November 2017.
Since then, Zimbabweans have seen a familiar pattern of dollar shortages battering the economy, rocketing inflation that is destroying the value of their savings and the government reacting forcefully to crush dissent.
In central Harare, shops, banks, fast-food chains and some government offices were closed with little traffic on the roads. There was no public transport and some people could be seen walking from townships into the city centre.
The government has blamed the protests on the main opposition and local rights groups, saying this was part of a plot to overthrow Mnangagwa's government.
"Ours is all about fuel. Ours is all about the skyrocketing prices of basic needs from fuel, health and food," said Kumbirai Magorimbo, while reading newspaper headlines in central Harare.
Activist pastor Evan Mawarire, who led a national shutdown in 2016, told Reuters that police had surrounded his house in a Harare suburb after he used Facebook posts to urge Zimbabweans to heed calls by the labour union to stay at home.
Econet Wireless Zimbabwe, the country's largest mobile operator, said its internet services had been cut off following an order from the government.
"We are obliged to act when directed to do so and the matter is beyond our control," Econet said in a text message to customers, adding that all networks and providers had suspended their services.
Internet services were cut by mid-morning on Tuesday, leaving many people without access to social media platforms amid accusations that the government wanted to prevent images of its heavy-handedness from being broadcast around the world.
Information Minister Monica Mutsvangwa told reporters on Tuesday that she was not aware of the blackout. (Editing by James Macharia and Jon Boyle)