Image copyright Getty Images Image caption Defence Secretary Michael Fallon thanked UK personnel tackling IS on the front line during a trip to RAF Akrotiri in Cyprus

Military action in Syria must be matched with "urgent funding" to support veterans who return with mental health problems, a charity has said.

Combat Stress said it was already "struggling to cope" with the number of former soldiers needing treatment.

The charity, which is treating nearly 6,000 veterans for conditions such as PTSD, said it expected numbers to rise as the Syrian conflict develops.

In 2014 the government said it was investing £7.4m to improve services.

RAF air strikes are continuing in Syria after British forces joined allied operations to target so-called Islamic State militants in the country.

But Combat Stress warned it might not be able to afford to support veterans affected by the conflict in the future.

The charity said it was taking a seven-figure sum from its reserves to keep its services running, including three rehabilitation centres, but a spokesman warned if no additional funding was found then services would have to be cut.

In the last financial year referrals to the charity for conditions such as post-traumatic stress disorder (PTSD), anxiety and depression went up by nearly 25% from 1,819 in 2013-14 to 2,328 in 2014-15.

Robert Marsh, fundraising and communications director, said: "Following a decade of military action in Iraq and Afghanistan, we are now struggling to cope with the thousands of veterans seeking our specialist mental health services.

"With MPs supporting further military action, we urgently need the financial resources to ensure our unique service continues to help the thousands of brave veterans who deserve the very best treatment."