Bangladesh on Monday extended a strict nationwide lockdown, confining people to their homes for another week as coronavirus cases and deaths both hit new records.

Authorities said a record 164 people had died in the previous 24 hours, while almost 1,000 tested positive -- the most single day-infections since the first case was detected in March last year.

Nazrul Islam, a top virologist and member of a high-powered national technical committee that asked the government to extend the lockdown, said the situation is "extremely bad".

"The Delta variant is responsible for 70 percent of the infections. This variant is highly transmissible. And we still have not seen the peak yet," he told AFP.

Bangladesh has so far reported nearly 950,000 infections and more than 15,000 deaths, figures experts say are likely to be three to four times less than the actual caseload and fatalities.

Under the lockdown imposed at the start of the month, and now extended until July 14, Bangladesh's 168 million people can only leave home for emergencies and to buy essentials.

The army and police are patrolling the streets, there is no public transport and shops and offices are shut. Food markets can open for a few hours a day.

In the capital Dhaka, home to some 20 million people, authorities have arrested more than 2,000 people for breaching lockdown rules.

Garment factories, a key pillar of Bangladesh's export-oriented economy, are exempted from the shutdown.

The health department said some 50 percent of infections are occurring outside the cities, with districts bordering India, where the Delta variant first originated, worst hit.

"The situation is worsening every day. The lockdown seems to be working. We hope the extension of the lockdown will improve the situation," a spokesman of the health department told AFP.