Pakistan said Saturday it has detected two new cases of coronavirus, bringing the total number of patients with the infection in the country to four.

Confirmation of the cases has set off alarm bells as authorities scramble to screen hundreds of people who recently arrived from Iran, a major new hotspot for the .

"One of the two patients has tested positive in the capital Islamabad and the other one in Karachi," the 's advisor on health Zafar Mirza told a press conference.

The earlier two cases were also detected in the same cities. Mirza said they were "fast recovering" and one would be discharged from hospital soon.

He said the government would further reinforce surveillance measures at with Iran and other neighbouring countries.

A senior official at the health department for Sindh province said "the patient undergoing treatment in Karachi has a recent history of travel to Iran from where he acquired the virus".

But no information was immediately available about the patient being treated in Islamabad.

There are growing fears in Pakistan, sandwiched between China and Iran, which are both fighting major outbreaks, about the country's ability to deal with the illness.

Islamabad has a history of failing to contain such as polio, tuberculosis and hepatitis.

The virus has now killed more than 2,900 people and infected over 83,000 worldwide, with an increasing number of new cases being reported each day.

Mirza said top government officials have decided "a national campaign will be launched to create greater awareness among the people about coronavirus and precautions".