They are the brave voices trying to tell the story of a brutal civil war but their numbers are dwindling.

In just the last nine months, six Syrian journalists have been assassinated by so-called Islamic State.

Some have had their throats slit whilst others have been shot in broad daylight.

Watch the video report:

Shockingly, some of these murders didn't happen in war-torn Syria, but in the supposed safety of neighbouring Turkey.

It is a sinister new front opened up by the IS, as it wrestles to control the narrative of what is happening in Syrian towns like Raqqa.

The men and women who were killed knew the risks, but they carried on anyway determined to witness and document the savagery of a murderous regime.

One day their accounts and evidence may form the basis of prosecutions for genocide and crimes against humanity.

'When IS killed Zahir they thought all the reporting would stop, but it is just the opposite' Credit: ITV News

World Press Freedom Day, which is being observed today across the world, stresses the freedom of information as a basic human right.

But it is well documented that Syria has become an incredibly dangerous place to operate as a journalist, now ranking 177th out of 180 countries on the World Press Freedom Index.

In 2015, it became the second most deadly place for reporting, just behind Iraq.

This comes in a year reported as having been the worst in 12 years for press freedom worldwide, according to a new report out this week, which attributes this to political, criminal and terrorist forces.

Yet at present there does not seem to be enough protection for the Syrian journalists and activists in Turkey who have received death threats from the black clad thugs who have so badly distorted a religion of peace.

During my visit I gauged a growing sense of alarm among the Syrian journalists who have sought safety across the border in Turkey.

Rashid al-Tabshi has gone into hiding Turkey Credit: ITV News

Rashid al-Tabshi is so worried he's gone into hiding.

He has regularly reported on the horrors of IS, but after the spate of killings he has changed homes and changed cities, hoping he's put himself beyond the reach of IS.

"I think [the killings send] a powerful message: we can reach you wherever we want, whenever we want ... You ask me if I am next. Maybe.

"I think they have a list and every one month or two months, or three months, they pick another name from the list, just to keep sending this message to the people."

But the defiance of the Syrian journalists and activists I speak to is staggering.

Ayman Mohammed runs a small news agency from Gaziantep called the Baladi News Network.

"I'm not scared of anything – there are people who are working as correspondents right where the shelling is taking place ... so if I think about them, then I would be ashamed to say I am scared.

"How can I say my life is hard here in Turkey?"

Zahir al-Shurqat was killed in broad daylight by a masked gunman in Turkey

The most recent killing is that of Zahir al-Shurqat, who presented a online television channel.

He was killed in broad daylight by a masked gunman in south-eastern Turkey. Hundreds attend his funeral.

Al-Shurqat is one of six Syrians killed by IS in the past nine months. The others were:

Ahmed Mohamed al-Mousa - a 23-year-old journalist who was working inside Syria

Ibrahim Abd al-Qader - a 22-year-old writer, murdered in a Turkish apartment

Fares Hamadi - a colleague of al-Qader's whose death was claimed by IS

Ruqia Hassan Mohammed - who wrote about daily life in Raqqa and is believed to have been killed after her postings suddenly stopped

Naji Jerf - a 38-year-old documentary maker

I met one of al-Shurqat's cousins at his graveside.

He preferred to remain anonymous but told me: "When IS killed Zahir they thought all the reporting would stop, but it is just the opposite - we will keep going we want to show Islam is not about terror groups."

He is defiant, as so many I spoke to in Turkey are: "They thought they could put fear into us and they would silence us but we will carry on telling the truth."

In order to continue telling the truth, they will need help from the authorities.

Speaking to ITV News on World Press Freedom Day, veteran investigative journalist Carl Bernstein, who along with Bob Woodward broke the Watergate scandal story in the 1970s, issued a call for action to protect journalists, saying he hoped world leaders would "do what they can to get safe passage for Syrian reporters who are under fire".

Watch Carl Bernstein's message on World Press Freedom Day:

We often hear Western leaders talk about the threat to Western values that IS poses, yet a free press is a bedrock of Western society and little appears to be being done to protect those risking their lives for it in Syria or Turkey.

Organisations such as Reporters without Borders and the International Press Institute (IPI) have called on the Turkish government to do more.