The United States Army has grounded its fleet of about 400 Chinook helicopters after a “small number” of engines fires were discovered, The Wall Street Journal reported on Tuesday.

An Army spokesperson told the American publication that fuel leaks led to engine fire incidents among an “isolated number” of the helicopters in recent days. “The safety of our soldiers is the Army’s top priority, and we will ensure our aircraft remain safe and airworthy,” the spokesperson said.

No injuries or deaths have occurred because of the fuel leaks or engine fires.

The US Army Materiel Command grounded the fleet “out of an abundance of caution”, The Wall Street Journal reported.

Engine-maker Honeywell said aircraft components called O-rings used in some of the helicopters did not meet the company’s design specifications. Honeywell worked with the Army to identify the problem but declined to name the company that had manufactured or installed the problematic components.

The helicopters are made by American defence manufacturer Boeing, which has declined to comment about the development.

The Chinooks, originally known as CH-47, are also in service in India, Britain and nearly 20 other countries. The helicopters can carry heavy loads and are used in combat as well as other critical operations.

The Indian Air Force is continuing the operations of its fleet of 15 Chinooks and has sought details from Boeing about the reasons behind the grounding in US, government officials told ANI.

In 2019, India had received the first batch of Chinooks from the US. They are used mainly in high-altitude regions such as Ladakh and Siachen Glacier, NDTV reported.