HONG KONG (AP) — Hong Kong suspended use of the Pfizer vaccine Wednesday after its Chinese distributor informed the city that one batch had defective bottle lids.

The city’s government said the suspension was immediate while the matter is investigated by distributor Fosun Pharma and BioNTech, the German company that created the vaccine with American pharmaceutical firm Pfizer.

BioNTech and Fosun Pharma have not found any reason to believe the product is unsafe, according to the statement. However, vaccinations will be halted as a preventive and safety measure.

The defective lids were found on vaccines from batch number 210102. A separate batch of vaccines, 210104, will also be not be administered.

The semi-autonomous territory of Macao also said Wednesday that its residents will not receive the Pfizer shots from the same batch.

The vaccines from the batch comprise a total of 585,000 doses, with the other batch number 210104 holding 758,000 doses, according to Hong Kong’s Director of Health Constance Chan.

Although about 150,000 doses from the batch 210102 have been administered in the city so far, officials said during a press briefing Wednesday that the vaccines were safe to use despite the packaging defects, and that suspending the vaccination was a precautionary measure. Batch number 210104 remains in the warehouse and has not been used.

Chan said that there were over 40 instances when medical personnel found defective packaging, such as cracks on the vaccine bottles or leakages when the vaccine was diluted with saline before being administered.

None of these vaccines was given to residents and they were thrown away, officials said.

“Fosun has promised to carry out an immediate investigation so they are going to approach the manufacturer in Germany to look into their plant,” Chan said. “When the vaccines arrive in Hong Kong, they will have a review of the whole logistics chain to see if that’s the cause of the current situation.”

She said that officials are urging manufacturers to give a report as soon as possible to check if the batches of vaccines in Hong Kong can be used, otherwise the manufacturers will have to deliver another batch of shots as soon as possible.

Residents who are slated to receive their second Pfizer dose starting on Saturday should get the second shot administered as soon as possible, if new vaccines arrive in Hong Kong after the recommended 19- to 42-day window following the first dose.

BioNTech could not be immediately reached for comment.

Fosun Pharma said in a filing to the Hong Kong stock exchange that it received notice from BioNTech regarding the packaging defects on Tuesday night and informed Hong Kong and Macao authorities on Wednesday to temporarily suspend the vaccines.

The suspension of the Pfizer jab means the only vaccine currently offered to residents is China’s Sinovac. The two vaccines are the only ones that were offered to residents in Hong Kong.

German expatriate Jannis Partsafas was among a group of people who received the Pfizer shot ahead of the suspension.

“I got vaccinated this morning at 8.30 a.m. before the news went public about the vaccine suspension, and heard the news when I was on my way home,” said 32-year-old Partsafas, who works in the sporting goods industry.

“I’m not very concerned about the safety, but I am worried that this may mean more people will turn down the option of getting vaccinated in Hong Kong which would impact herd immunity and the lifting of social-distancing measures,” he said.

Some residents who had appointments to receive the Pfizer shots stood in line outside a community center in the city’s Sai Ying Pun neighborhood at about 10.30 a.m. They eventually left when it became clear the vaccines would not be administered.

As of 8 p.m. Tuesday, 403,000 people have received vaccines in the city, of which 150,200 had received the first dose of the Pfizer vaccine, compared with 252,800 who had taken the Sinovac jab.