Austrian authorities have suspended inoculations with a batch of AstraZeneca’s COVID-19 vaccine as a precaution while investigating the death of one person and the illness of another after the shots, a health agency said on Sunday.

“The Federal Office for Safety in Health Care (BASG) has received two reports in a temporal connection with a vaccination from the same batch of the AstraZeneca vaccine in the district clinic of Zwettl” in Lower Austria province, it said.

One 49-year-old woman died as a result of severe coagulation disorders, while a 35-year-old woman developed a pulmonary embolism and is recovering, it said. A pulmonary embolism is an acute lung disease caused by a dislodged blood clot.

“Currently there is no evidence of a causal relationship with the vaccination,” BASG said.

Swiss newspaper Niederoesterreichische Nachrichten as well as broadcaster ORF and the APA news agency reported that the women were both nurses who worked at the Zwettl clinic.

BASG said blood clotting was not among the known side effects of the vaccine. It was pursuing its investigation vigorously to completely rule out any possible link.

“As a precautionary measure, the remaining stocks of the affected vaccine batch are no longer being issued or vaccinated,” it added.

AstraZeneca had no immediate comment when contacted by Reuters.

The APA news agency quoted AstraZeneca as saying the company was in contact with Austrian authorities and would fully support the investigation.

It noted the vaccine had been approved by the European Medicines Agency and the World Health Organization based on a global clinical program involving 23,000 participants.

“All of these evaluations have concluded that the AstraZeneca COVID-19 19 vaccine is safe and effective,” APA quoted the company as saying.

European Union regulators on Jan. 30 approved the product, saying it was effective and safe to use. Adverse reactions seen in trials were short-lived for the most part and blood clotting issues were not reported.