SAN FRANCISCO (Reuters) - The many medical claims by veterans of U.S. wars in Iraq and Afghanistan has completely overwhelmed the American government, leading to “shameful failures” in treatment, a class-action lawsuit filed on Monday alleged.

A view of the main entrance to Walter Reed Army Medical Center in Washington in this February 9, 2007 file photo. The many medical claims by veterans of U.S. wars in Iraq and Afghanistan has completely overwhelmed the American government, leading to "shameful failures" in treatment, a class-action lawsuit filed on Monday alleged. REUTERS/Yuri Gripas/Files

“Because of those failures, hundreds of thousands of men and women who have suffered grievous injuries fighting in the ongoing wars in Iraq and Afghanistan are being abandoned,” according to the lawsuit filed in the U.S. District Court for Northern California.

More than 1.5 million U.S. service members have been sent to Iraq or Afghanistan since 2001.

Repeated and extended deployments to war zones have driven a rise in post-traumatic stress among troops. But Pentagon and Veterans Affairs Department lack the resources and staff to help service members, according to recent reports.

The filing by two veterans groups sued various officials in the Department of Veterans Affairs and U.S. Attorney General Alberto Gonzales and challenged the constitutionality of a 1988 law establishing various VA practices. The two plaintiff organization represent about 12,000 American veterans.

“Unless systemic and drastic measures are instituted immediately, the costs to these veterans, their families, and our nation will be incalculable, including broken families, a new generation of unemployed and homeless veterans, increases in drug abuse and alcoholism, and crushing burdens on the health care delivery system and other social services in our communities,” the suit said.

The suit said the Department of Veterans Affairs faced a backlog of 600,000 claims, with some veterans dying while waiting to settle claims. It also claimed the VA was unable to deal with the growing number of Post-Traumatic Stress Disorder cases.

A spokesman for the Veterans Affairs Department was not immediately available.

In April President George W. Bush announced a government plan to improve health care and related services for U.S. troops and returning veterans.

The General Accountability Office reported last year that the Pentagon referred only 22 percent of U.S. troops returning from Iraq and Afghanistan with signs of Post Traumatic Stress Disorder for mental health evaluations.