By Moazzem Hossain BBC reporter in Dhaka

The Bangladesh authorities have called in hundreds of volunteers to battle dengue fever in the capital, Dhaka.

The outbreak, the second worst in the city's history, has killed 25 people since last month.

Every single bed in the specialised child hospital was occupied

Rifat Bhuiyan, Dhaka resident

About 100 patients are turning up at city hospitals every day, officials say.

Health workers, meanwhile, say they are running short of blood supplies with which to treat patients, and many hospitals lack test kits used to detect the mosquito-borne disease.

In the space of just over a week, the total number of people infected with dengue in Dhaka has nearly doubled. Officials say 1,950 cases of dengue infection have so far been reported to the Health Ministry control room.

In the last few days, however, the number of patients has increased dramatically.

On Tuesday, 93 new dengue patients were admitted to city hospitals, and another 87 patients had been added to the list by midday on Wednesday.

Doctors' leave cancelled

But many people in Dhaka question the official figures. They say more patients are being treated at home.

The Aedes mosquito carries the fever

Rifat Bhuiyan, a resident of Dhaka's Dhanmondi area, said five members of her family had been infected - and all were being treated at home.

"When I rushed to the hospital early in the morning with my five-year-old son, who had been diagnosed with dengue infection, there was no room for him," she said.

"Every single bed in the specialised child hospital was occupied.

More than 60 people were queueing at the counter

Dr Shahana Jafar, Dhaka blood bank

"There were many more dengue patients coming to the hospital who were turned back."

Health Minister Khondaker Mosharraf Hossain admits officials are concerned about the situation, and says the deadly fever is now spreading to other parts of the country.

On Tuesday, he ordered all leave for doctors and health workers who were trained to combat dengue fever to be cancelled.

Anti-mosquito campaign

At Dhaka's main blood bank, which is run by the International Red Cross and Red Crescent Societies, supplies are failing to cope with the increased demand.

Tuesday was one of the busiest days they had ever experienced.

"More than 60 people were queueing at the counter," Dr Shahana Jafar, who is in charge, told the BBC.

"But we couldn't supply more than 20 bags of blood a day."

Newspapers in Dhaka have been strongly critical of city council officials for failing to launch a mosquito eradication campaign in time.

Dengue virus is carried by a particular type of mosquito and the post-monsoon period is considered its ideal breeding season.

To combat the situation, Dhaka city corporation has sought the help of hundreds of scouts and volunteers for a cleanliness drive and awareness-raising campaign.