Thousands of doses of the faulty medicines were freely provided to patients with heart problems at the government-run Punjab Institute of Cardiology in the eastern city of Lahore.

"We are trying to retrieve all the medicines given out at this hospital," said Jehanzeb Khan, the Punjab health secretary. Thousands of prescriptions were handed out at the facility in the last month, hospital officials said.

Investigators suspect bits of metal in the pills are responsible for the symptoms, which include heavy bleeding.

Over 100 people have been admitted to hospitals in Lahore because of symptoms caused by the faulty medicines.

Sources at the Punjab health department told Reuters that the death toll from the medicines is much higher than the official count.

The government has banned five drugs believed to be contaminated, and police have arrested three people in connection with the deaths.

At least one pharmaceutical factory, not named by police, has been sealed.

The provincial government formed a committee to probe the deaths. Faisal Masood, a member of the committee, said the deaths began last month.

"Patients were coming in with symptoms similar to dengue fever. But then we realized it wasn't that," he said.

"The one thing common in all patients was heart disease, and that they were getting medicines from the Punjab Institute of Cardiology."

Pakistan's cash-strapped government, accused of ineptitude and corruption, spends little on health and many Pakistanis have little faith in state-run medical centers.

(Writing by Qasim Nauman and Rebecca Conway Editing by Chris Allbritton and Ed Lane)

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