A sudden spate of suicides in the Canadian armed forces has raised urgent questions about care for Afghanistan veterans amid criticism of the government for failing to provide mental health support professionals for soldiers.

Four men have killed themselves in the past two weeks. The latest was Master Corporal Sylvain Lelievre, 46, who was found dead at his military base near Quebec City on Monday. He had served in Afghanistan and in Bosnia during his nearly 30-year career.

The Canadian military is investigating the recent apparent suicides of Warrant Officer Michael McNeil at a base in Ontario, Master Corporal William Elliott in Manitoba and Master Bombardier Travis Halmrast, who was being held on domestic assault charges in an Alberta correctional facility.

According to Canada's department of national defence, nearly 50 soldiers have killed themselves between 2010 and 2012.The deaths prompted army top brass to release a video message urging soldiers to seek help. They also generated questions in parliament, where opposition leaders accused the government of a lack of compassion and asked what was being done to address the "unprecedented" death toll.

The prime minister, Stephen Harper, said earlier this week that "supports are available and we'll make sure that they continue to be available to those people". He said it was "everyone's responsibility to encourage those who need support … to get help".

At its peak, the Canadian detachment in Afghanistan numbered 3,000 soldiers. The Canadian combat role was wound down in 2011, but the country has committed to providing military training assistance to the war-torn country until 2014.

Its experience of suicides mirrors that of the US and UK, where army chiefs have been warned of the rising tide of post-traumatic stress disorder (PTSD). The illness takes on average 11 years to manifest itself, meaning that countries that had extensive involvement in Iraq and Afghanistan in the first decade of the 21st century can expect a serious outbreak in this the second. In 2012, more US service members took their own lives than were killed in combat.

Controversially, nine regional centres in Canada that provided services to veterans are due to close. Many of those services are being moved online or handled by a 24-hour toll-free telephone helpline.

The country's military ombudsman has been pushing Canadian authorities to hire more mental health support professionals for soldiers. A 2002 target of 147, set by the military, has yet to be met. His veterans affairs counterpart said soldiers needed to be assured of greater financial stability.

Master Corporal Kristian Wolowidnyk, a former combat engineer and Afghan war veteran, said he had tried to kill himself last month – two days after he was informed he would be discharged on the grounds of his PTSD. "If I have tried and failed, there are obviously other people thinking about it," he said in a CBC interview.

Wolowidnyk has since been told he now qualifies for a prolonged release process for injured soldiers – which means he will qualify for a fully indexed military pension. His wife described the mental illness suffered by Afghan war veterans as an epidemic. She and her husband said help was hard to get.

Major Marc Dauphin, a military surgeon, led the multinational hospital at Kandahar airfield in 2009. "It was 24/7, one of the busiest trauma hospitals in the world," he told the CBC this week.

He said: "War weaponry is designed to tear the human body apart – and it works." Four months after returning to Canada, he started suffering panic attacks and his marriage began falling apart. He said he considered throwing himself into a freezing river. Instead, he decided to get help. Even he didn't realise he was suffering from PTSD.

Last month Kevin Berry, an Afghan war veteran and PTSD sufferer, wrote a scathing open letter to Canada's veterans affairs minister, Julian Fantino. "When veterans want help, they turn to their friends or Google, not a government that has a reputation for denying benefits and treating veterans as burdens … Your government, Sir, is not living up to its duty to veterans," he wrote.

This week, Canada's highest-profile PTSD sufferer, the retired general Romeo Dallaire – now a Canadian Liberal senator – smashed his car into a post on Parliament Hill.

"I was out cold," said the former commander of the UN peacekeeping force in Rwanda. He reflected that the reports of the soldiers' deaths and the impending 20th anniversary of the Rwandan genocide had caused him to have sleepless nights – even with strong medication.

He has described government cuts to veterans affairs and national defence as ruthless as they put mentally injured war veterans and their families at risk.