A bomb disposal unit has been called in to deal with an incident at the Wrexham Industrial estate, where AstraZeneca's anti-coronavirus vaccine is made and stored, the BBC reported, adding that North Wales police are also working at the site.
The broadcaster said a cordon had been put in place near the plant of the Pharmaceutical company, with the public instructed to stay away from the spot.
Later in the day, the pharmaceutical company Wockhardt UK said that a suspicious package that was found at the facility had been made safe and would be analysed by police.
"We can confirm that the investigation on the suspicious package received today has been concluded. Given that staff safety is our main priority manufacturing was temporarily paused whilst this took place safely. We can now confirm that the package was made safe and staff are now being allowed back into the facility", an official statement said.
"This temporary suspension of manufacturing has in no way affected our production schedule and we are grateful to the authorities and experts for their swift response and resolution of the incident", the company added.
The plant in Wrexham, which is capable of producing as many as 300 million doses of the vaccine a year, inked an agreement in August, at the height of the pandemic, to help prepare the inoculation for distribution across the nation.
In particular, it is responsible for putting the vaccine in vials and packaging it for dispatch to the UK regulator for inspection, FT wrote earlier this month.
"We are immensely proud to have been selected to partner with the UK government on this project", Ravi Limaye, managing director, said when the state contract was first announced.
"We have a sophisticated sterile manufacturing facility and a highly-skilled workforce", he went on to praise their assets.
Apart from ambitious goals to deliver the British-Swedish inoculation to the EU, the UK has recently launched the biggest mass vaccination programme within its borders, aimed at protecting tens of millions of people from COVID-19 within months.
The government intends to offer vaccines to 15 million people - those over 70s, healthcare workers, and those required to shield - by mid-February, and millions more of the over 50s and the rest of the priority groups by spring. Those categories are believed to make up to 90-99% of those at risk of dying from the highly contagious infection.