US Army officials have raised alarm over the quality of five million inserts added to bullet-proof vests that were provided to US troops participating in two wars.

According to a Pentagon report, the inserts made of synthetic fibres known as Kevlar or ceramic may not meet standards due to poor ballistic testing and quality assurance.

“The army lacks assurance that 5.1 million ballistic inserts acquired through the seven contracts provide appropriate protection,” the report added.

As per quality control standards, inserts were required to be tested at temperatures of 58°F to 78°F with humidity levels of around 40%-60%, according to Agence France Presse.

The report, however, found that the test conditions were not met in 52% of the cases.