WASHINGTON (Reuters) - A gun control group to prevent suicides among U.S. veterans has been formed by retired U.S. Central Intelligence Agency chief David Petraeus and former astronaut Mark Kelly, it said on Friday.

About 22 U.S. veterans commit suicide every day and almost 70 percent kill themselves with a firearm, the Veterans Coalition for Common Sense said in a statement, citing government data. Veterans are often afflicted with depression and Post-Traumatic Stress Disorder.

The coalition will lobby to close loopholes in background check laws and partner with other veterans groups to boost mental health, it added.

Kelly, a former Navy captain, became a vocal gun control advocate after his wife, former Arizona congresswoman Gabrielle Giffords, was shot in the head in 2011 in an assassination attempt. In 2013 the couple formed another gun control group, Americans for Responsible Solutions.

Petraeus, a retired four-star general, resigned as director of the CIA in 2012 after it was revealed he was having an affair with his biographer.

The coalition's advisory committee includes former CIA director Michael Hayden and Stanley McChrystal, former commander of U.S. and North Atlantic Treaty Organization forces in Afghanistan.

(Reporting by Ian Simpson)