Heart drugs distributed for free by the government-run Punjab Institute of Cardiology in Pakistan have led to the death of at least 27 people over the past month, and the owners of two local pharmaceutical firms have been arrested.

The faulty drugs are believed to contain bits of metal that can cause fatal bleeding. Over 100 people have been treated for adverse reactions related to the drugs.

The names of the local pharmaceutical firms involved have not been released by authorities, but the provincial government of Punjab has formed a committee to probe the deaths.