Zimbabwe's state-run newspaper appeared to threaten a British diplomat it accused of supporting government opponents on Tuesday, suggesting on its front page that she could be welcomed home "in a body bag" if she persisted.

Britain immediately summoned the Zimbabwean ambassador in London to explain the article in the Herald, calling the threats "shocking and absolutely unacceptable."

Tensions in Zimbabwe have been high since police violently broke up a prayer meeting last month, detaining and severely beating the country's most prominent opposition leader and other members of the Movement for Democratic Change. President Robert Mugabe has warned opponents they will be "bashed" again if they incite unrest and has threatened to expel Western diplomats if they meddle in local politics.

Trucks of riot police drove through Zimbabwe's capital and military helicopters flew overhead Tuesday on the first day of a national strike to protest deepening economic hardships blamed on Mugabe's government.

On Tuesday, the Herald newspaper made what seemed like a death threat against British Embassy political officer Gillian Dare, calling her the "the purse holder and financier" of an alleged terror campaign by the Movement for Democratic Change.

"It will be a pity for her family to welcome her home at Heathrow Airport in a body bag just like some of her colleagues from Iraq and Afghanistan," said an article on the newspaper's front page.

Dare, "labeled in some sections of the media as a British spy, could one day be caught in the crossfire as she plays night nurse to arrested MDC hooligans," the newspaper said.

A British Foreign Office spokeswoman called the threats "shocking and absolutely unacceptable" and said Zimbabwe's ambassador was called to a meeting in London with Permanent Undersecretary Peter Ricketts, who "emphasized that we expect Zimbabwe to offer protection to our diplomats."

Dare remained at the embassy working as normal, she said, speaking on the government's customary condition of anonymity.

During Tuesday's strike, soldiers armed with automatic rifles stood at intersections in Harare's main industrial district where some factory gates were closed, along with several banks, shops and fast food stands. Most downtown shops were open, and commuter buses were full of passengers.

Zimbabwe's main trade unions called the two-day strike to protest an economic crisis that has brought 80 percent unemployment, the world's highest inflation rate — 1,700 percent — and acute shortages of food, hard currency and gasoline.

Labor unions planned no street demonstrations for fear of provoking police action.

Mugabe's crackdown dissent has brought international condemnation, though he received a boost last week when southern African leaders publicly backed him at a summit.

He has blamed the economic crisis on sanctions imposed by Britain, the United States and other Western countries. Western governments say the sanctions, including asset freezes and a travel ban on Mugabe and 100 of his top associates don't hurt most Zimbabweans.

The Congress of Trade Unions blames the meltdown — Zimbabwe's worst since independence in 1980 — on government corruption and mismanagement. Mugabe's government disrupted the agriculture-based economy in 2000 with violent seizures of white-owned commercial farms, part of a program to redistribute land to poor blacks.

Military helicopters swooped over downtown Harare in a show of force and later flew over the nearby Epworth township. Water canon and trucks of riot police drove through the city center. Four trucks carrying soldiers were seen headed to the southern town of Chitungwiza.

Executives at one Harare engineering plant said its workers planned to ignore the strike because the lunch provided in the canteen was the only daily meal they could rely on. Other workers feared their pay would be withheld.

An electrical store kept one of its main entrances shut, a practice seen in previous strikes enabling businesses to close hurriedly in case of unrest.

"It's patchy, but it looks like a military occupation down here," said a factory owner in eastern Harare who asked not to be identified. "We've left it to our people to decide what to do. A few haven't arrived."

Police ordered township shops and bars to close early Monday evening as paramilitary police were deployed and water cannons patrolled.

Security measures were in place to keep schools open on the last day of the term before the Easter break, Information Minister Sikhanyiso Ndlovu told state radio. He described the strike as "irrational" and insisted the government was "doing all it could to address the current economic challenges facing the country."