The Pakistani factory blamed for killing more than 100 people with tainted heart medication is closed.

Pakistani officials shuttered the facility in Karachi Thursday after tests done in London showed the pills contained high levels of an anti-malarial chemical that poisoned the heart patients.

All the victims were from Pakistan's Punjab province. Authorities previously arrested the owners of at least two pharmaceutical firms that supplied the government-owned Punjab Institute of Cardiology with the tainted drugs.