HONG KONG (AP) — Hong Kong suspended vaccinations using BioNTech shots Wednesday after they were informed by distributor Fosun PHARMA that one batch had defective bottle lids.

The suspension was immediate while Fosun PHARMA and BioNTech, the German company which created the vaccine with American pharmaceutical firm Pfizer, investigate the matter, according to a statement by the Hong Kong government.

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 210202. A separate batch of vaccines, 210104, will also be not be administered.

Macao said Wednesday that residents would not receive BioNTech vaccinations from the affected batch.

All community centers in Hong Kong administering the BioNTech vaccine have temporarily suspended vaccinations, and residents who already made appointments for Wednesday need not proceed to the centers, the government said.