Six patients tested positive for Zika virus in Uttar Pradesh’s Kanpur district, ANI reported on Sunday. The tally of cases in the state rose to 10, according to Kanpur’s Chief Medical Officer Dr Nepal Singh.

Among the 10 cases, three patients are Indian Air Force personnel and the remaining seven are all civilians, according to the Hindustan Times. The patients will remain under supervision for 14 days.

The Zika virus is transmitted primarily by the Aedes mosquitoes, which bite during the day, according to the World Health Organization. It can also be sexually transmitted. Symptoms of the infection include fever, rashes, headache and joint pain.

The Kanpur chief medical officer added that the area within the three-kilometre radius of a patient’s location will be screened.

An unidentified official told that a pregnant woman is among the 10 patients. “She is being monitored. A gynaecologist visited her from Delhi to assess her medical parameters,” the official added.

An official from the National Vector Borne Disease Control Programme said that at least 600 samples of close contacts of the 10 Zika patients have been sent to King George’s Medical University for testing.

A team from the central government has also collected samples from Aedes Aegypti mosquitoes in Kanpur. The virus from these mosquitoes will be isolated and tested in the National Institute of Malaria Research.

“We are tackling this problem at a war footing,” an unidentified official from the National Vector Borne Disease Control Programme told “There may be more Zika cases in the next few days but we are hopeful we will contain the spread to Kanpur. This will not spread to other districts.”

The state health department on Monday found Zika larva in a park across the street in Shyam Nagar in Kanpur, where one of the patients was found, the Hindustan Times reported.

“We have pointed out 117 mosquito breeding points in these [10] localities and they all have been destroyed,” the Kanpur chief medical officer said. “Fifty malaria control teams are constantly looking out for such points for source reduction.”

But health officials are yet to ascertain the source of infection in the Indian Air Force officer’s case in Kanpur. The airforce official was the first person to contract the virus. He did not have a travel history.

However, mosquito breeding spots were found in the neighbourhood of his residential premises and in water tanks of the Indian Air Force office.

Data till October 31 accessed by showed that at least 12,729 households had been surveyed for mosquito larvae breeding, and it was detected in 296 houses.

At a high-level meeting in Lucknow on Sunday, Chief Minister Adityanath asked the health department to curb the spread of the disease, The New Indian Express reported.

“The health department must ensure strict surveillance to check the spread of Zika virus and should undertake frequent and extensive door-to-door sanitisation and fogging drives to stop mosquito breeding,” he said. “People should be made aware of preventive measures and must be encouraged to maintain cleanliness.”

Maharashtra and Kerala too have reported cases of the Zika virus this year.