BERLIN — German Chancellor Angela Merkel on Tuesday said the country will halt the use of AstraZeneca's coronavirus vaccine for people younger than 60 because of concerns that it is causing rare but occasionally fatal blood clots.

Merkel said that the government “cannot ignore” a recommendation for such a move by the country’s vaccine committee and new data about blood clots developing following shots with the vaccine developed by the Swedish-British pharmaceutical giant AstraZeneca and the University of Oxford.

Germany’s medical regulator, the Paul Ehrlich Institute, said earlier that it had recorded 31 cases of cerebral venous thrombosis, a rare brain clot that can result in hemorrhaging, among 2.7 million people in the country that have received the AstraZeneca vaccine.

All were younger than 63, and all but two were women. Nine people have died.

"We all know that vaccination is the most important tool against the coronavirus," said Merkel, but she said there were other options for younger people.

“We are not faced with the question of AstraZeneca or no vaccine,” she said. “Instead we have several vaccines at our disposal.”

AstraZeneca said that “patient safety remains the company’s highest priority” and that a causal relationship between the vaccine and blood clots had not been established by British and European regulators.

“Regulatory authorities in the UK, European Union, the World Health Organization have concluded that the benefits of using our vaccine to protect people from this deadly virus significantly outweigh the risks across all adult age groups,” AstraZeneca said in its statement. Younger Germans will still be able to receive an AstraZeneca shot if they consult with a doctor and sign a waiver.

Some other countries that had paused AstraZeneca doses earlier this month had been more cautious about restarting vaccinations. France limited its use to people older than 55.

Norway, where regulators say four people died of blood clots among about 120,000 people who received the AstraZeneca jab, has continued its pause. Sweden has resumed AstraZeneca use for people older than 65.

The vaccine is not yet cleared for use in the United States, where the independent medical board overseeing its trials took the unusual move last week of accusing the company of providing an “incomplete view” of efficacy data in its U.S. trials.

After an initial review this month, the European Union’s medical overseer, the European Medicines Agency, had deemed the vaccine “safe and effective” but said it is continuing to investigate a possible link between the vaccine and blood clots.

The agency said that the benefits outweighed the risks, and it added a clot warning to the product about two weeks ago. At the time, it said that 25 cases were being investigated among 20 million jabs across Europe.

Germany had resumed use of the AstraZeneca shot following the recommendations, having recorded three deaths before pausing.

But there have been increasing calls from parts of the medical community to reassess. Of particular concern has been the risk for younger women, who have made up the majority of the clot cases in Germany.

In a letter to health authorities, the heads of five university hospitals in the German state of North-Rhine Westphalia, wrote that there was an “extremely unfavorable risk/benefit profile for the use of the AstraZeneca vaccine” for women ages 20 to 29 because of the unlikelihood of a coronavirus infection being fatal, according to excerpts carried by Germany’s DPA news agency.

While the EMA continues its investigations, experts in Germany and Norway who have treated patients suggest that the clots are caused by an immune response triggered by the vaccine.

Regulators in Britain, where the majority of AstraZeneca vaccines in Europe have been administered, said they had found five cases of clots as of March 14 but have not been updated on numbers since.

“There is a time lag between reports received and publication to allows us time to fully evaluate the data before we issue any conclusions on it,” it said.

A Canadian panel of scientists on Monday recommended against the administration of the AstraZeneca vaccine in people 55 and younger, citing “substantial uncertainty” over its benefits for that age group because of “rare” cases of clots reported in Europe.

Canada’s National Advisory Committee on immunization cast the guidance as a “precautionary measure” while Health Canada, the country’s drug regulator, investigates. It said the rate at which the clotting incidents occur is not known “with certainty.”

No such cases have been reported in Canada, which has administered about 300,000 jabs of the AstraZeneca vaccine.

The panel’s guidance is nonbinding, but Canadian provinces, which are responsible for the administration of vaccines, said they would follow the advice.

Amanda Coletta in Toronto contributed to this report.