Iran further eased restrictions aimed at curbing the spread of the novel coronavirus Tuesday by allowing restaurants to accept customers, as it announced another 57 deaths from the virus.

Since the first cases of COVID-19 appeared on its soil in mid-February, the Islamic republic has sought to halt the spread of the virus without imposing lockdowns.

A deputy health minister signalled the easing of restrictions on eateries. "Restaurants which before this decree were only allowed to distribute food will be allowed to accept customers from today," Mohsen Farhadi told state television.

Farhadi called on restaurants to respect health protocols to ensure distancing of two metres, a measure he said would reduce client numbers by 50 percent. Health ministry spokesman Kianoush Jahanpour reported 57 additional COVID-19 deaths in the past 24 hours, bringing the total number of fatalities in the country to 7,508.

Jahanpour said 1,787 new cases of infection over the same period brought the Islamic republic's caseload to 139,511. "We are seeing a stable process in the majority of provinces," Jahanpour said, adding that the southwestern province of Khuzestan was still classified "red", although the number of infected cases was declining.

Red is the highest level on the country's colour-coded scale of risk in relation to its coronavirus outbreak -- the deadliest in the Middle East. Experts both at home and abroad have voiced scepticism about Iran's official figures, saying the real toll could be much higher.