The Border Security Force (BSF) said on Friday that 30 more of its personnel had contracted the novel coronavirus, taking the total number of cases in the 10-lakh-strong central paramilitary forces to over 500.

In a statement, the BSF said 24 of the fresh cases were from Tripura and six from Delhi. “All of them are under the best available medical care at AIIMS (Jhajjar), Haryana, and at GB Pant Hospital (Agartala),” the statement said.

The BSF said that after the latest infections, the frequency of sanitisation of work places and barracks had been increased.

“Improvised methods like water cannons are being used for quick disinfection of buildings and establishments. Personnel are repeatedly sensitised to firmly adhere to preventive protocols,” the BSF, which guards the borders with Bangladesh and Pakistan, said.

Union home minister Amit Shah on Friday held a review meeting with the directors-general of all the central paramilitary forces and expressed concern over the increasing Covid-19 cases among the forces. “He discussed measures to be taken for containing the further spread of the disease in the paramilitary forces,” said a home ministry statement.

Four troopers — two from the BSF and one each from the CRPF and the CISF — have died due to Covid-19.

Sources said the infections had been reported as the troopers were engaged in operational and essential duties and that each establishment of the force had been following the standard operating procedure laid down to contain the disease.

The BSF is the worst-affected with 223 positive cases, followed by the CRPF with 162 cases. The ITBP has reported 82 so far. The CISF has reported 32 cases and the SSB 13.