Iran on Tuesday announced the highest number of cases of the novel coronavirus in a single day, with 3,712 people infected in 24 hours.

"We are seeing an increase in confirmed cases, and daily hospitalisations in most of our provinces," health ministry spokeswoman Sima Sadat Lari said in televised remarks.

"The rate of compliance with health protocols and wearing masks is declining," she warned.

The highest case number recorded before was on June 4, when 3,574 cases were detected, according to official figures.

Iran has been battling the Middle East's deadliest outbreak of Covid-19, with the death toll standing at 24,656 people out of a total of 429,193 people infected.

On Monday, Iran's supreme leader Ayatollah Ali Khamenei urged people to respect government health regulations, implying that Iranians are taking the threat of the virus lightly.

Iran took various restrictive measures to stem the virus but without ever imposing a full lockdown, with its economy already hit after the United States reimposed sanctions in 2018.

While regions have been coded with a traffic light style system of risk -- white, yellow and red -- the health ministry has said the whole country should now be considered "red".