NAIROBI — Pent-up anger found its vent on Monday in Zimbabwe as thousands crowded the streets of cities and towns nationwide to protest the mismanagement of an economy that has undeniably rotted to its core.

Just five months have passed since Emmerson Mnangagwa took over as president from Robert Mugabe, who ruled for nearly 40 years and presided over Zimbabwe’s initial catastrophic economic meltdown. But Mnangagwa, who won a contested election on promises of putting the country back in business, has made decisions that strike many Zimbabweans as a continuation of Mugabe’s misguided policies.

Mnangagwa deposed an increasingly erratic Mugabe with the help of the military in November 2017, but a subsequent election was marred by accusations of vote rigging.

On Sunday, just before taking a private jet on an official trip to Russia (all of the state-owned airline’s planes are grounded), Mnangagwa announced a 140 percent increase in fuel prices, raising the cost to $12.53 a gallon and making Zimbabwe by far the most expensive place to gas up in the world. For many Zimbabweans, it was the last straw. They took to the streets, but in another echo of the Mugabe era, so did security forces, looters and unidentifiable armed men.

According to the advocacy group Doctors for Human Rights, five people have died during the protests and nearly 40 have been treated for gunshot wounds in Chitungwiza, one of the capital Harare’s sprawling suburbs, and Kadoma, a town southwest of Harare. Security Minister Owen Ncube told state-owned media Monday night that more than 200 people had been arrested nationwide. Internet connections were also shut down in some areas.

“A number of people in plain clothes but armed with AK-47 rifles were video recorded shooting people in Harare. They are likely security agents not in uniform,” said Dewa Mavhinga, director for Southern Africa at Human Rights Watch.

The current crisis harks back a decade. Zimbabwe gained international notoriety in 2008 when its inflation rate ballooned to a ludicrous, record-breaking extent, prompting the government to print hundred-trillion-dollar notes. The result was that Mugabe scrapped the national currency and allowed Zimbabweans to use international currencies in local transactions.

Inflation is now at a more comprehensible 31 percent, according to official statistics, but the currency crisis has still devastated the economy and is threatening to tear the country apart.

The simplest explanation is that Zimbabwe lacks the foreign currency on which its economy is now premised. Zimbabwe’s foreign reserves can cover less than two weeks of imports, central bank data show, meaning that retailers of such necessities as food, medicine and gas are skittish about entering into contracts in the country. Without swift action to rebuild foreign reserves, the economy could implode.

Everything is in short supply. People wait overnight at gas stations to be the first in lines that can stretch miles. And at stores and restaurants, there are separate prices for those paying in precious cash vs. “mobile money” — which is akin to credit that Zimbabweans can access through their cellphone numbers.

There aren’t enough cash reserves in Zimbabwe’s central bank to back up the $10 billion trapped in people’s mobile accounts. This has led to the devaluation of those accounts, causing prices for mobile money transactions to be at least four times higher.

Critics of Mnangagwa’s price hike say it is a surreptitious attempt to raise taxes for the government at the expense of the common man. The new fuel price masks a sharp increase in the government’s excise tax, which follows a 2 percent increase in the tax on mobile money transactions that dominate the economy. Doctors and teachers have gone on short strikes, demanding to be paid in cash.

“Zimbabwe is burning while Emmerson Mnangagwa eats cake in his Dreamliner. If I were him, I would cancel the trip and address the discontent,” Fadzayi Mahere, a prominent lawyer in Harare, wrote on Twitter. “All Zimbabweans want is a better life and dignity — not a government that expects the people to ‘take the pain’ while they swim in luxury.”

The Zimbabwean government has tried to peg the protests on the opposition, which still has not accepted Mnangagwa’s victory in the July 30 election.

“It has become obvious that there is deliberate plan to undermine and challenge the prevailing constitutional order,” Nick Mangwana, a government spokesman, said in a statement late Sunday.

He said the government would “respond appropriately” against “all those who have been conspiring to subvert peace, law and order in the country.”

The opposition has lain low, and its leaders have not been spotted at the protests. On Monday night, the main opposition party, the Movement for Democratic Change, posted pictures on social media of its headquarters, which appeared to have been attacked with molotov cocktails.

Late Monday, Fastjet, one of the few airlines still serving Zimbabwe, canceled its remaining flights to and from the country.

Zimbabwe’s new fuel cost is far higher than in places such as Hong Kong, where mass transit is heavily subsidized, or remote island nations such as Iceland, where import prices are high.