Image caption Heavy fighting is continuing in Syria's second city Aleppo

Reports that Britons were among Islamist militants who kidnapped and wounded two photographers in Syria are being taken "very seriously" by ministers, the Foreign Office has said.

The claims were made by photographers John Cantlie and Jeroen Oerlemans, who were held at a camp for a week in July.

The Foreign Office said it was closely "monitoring the situation".

The Free Syrian Army group, which is part of the opposition trying to oust Bashar al-Assad, helped them to escape.

Mr Cantlie, who is British, and his Dutch colleague, Mr Oerlemans, were both wounded in a "shooting gallery" as their thwarted captors fired after the fleeing men.

The kidnapping took place amid the ongoing conflict in Syria.

Heavy fighting is continuing in the country's second city, Aleppo, amid concerns that the army will launch a full-scale assault within days.

Activists say more than 20,000 people - mostly civilians - have died in 17 months of unrest.

Jihadists - those committed to establishing an Islamic state by violent means - have started to be seen on the battlefield in Syria.

The FSA is said to be scrutinising jihadists in Syria very closely.

They are considered to be "a real threat after the Assad regime falls", a senior FSA officer told the BBC.

Mr Cantlie told BBC Radio 4's Broadcasting House programme he and his colleague were regularly threatened with death.

"When you're held captive, you're blindfolded and you have a guy sticking a gun at your head, it's very real," he said.

"It was inferred that we would meet our God. We had sowed the seeds of our own destruction. We would be shot or beheaded.

"At one point they even started sharpening knives for a beheading. It was pretty frightening."

I think these are disenchanted young men from the UK who are now unified under this jihadist banner John Cantlie, Photojournalist

The photographer said he entered Syria across the border with Turkey, using the same route and guide that he had earlier in the year.

But on this occasion he and his companions were detained after passing through a camp inhabited by Islamic jihadists who, he said, were not from Syria.

"They were from anywhere but Syria," he told the BBC.

"They were from Pakistan, Bangladesh, the UK and Chechnya. A real mix."

He said there were "between 10 and 15 young jihadists from the UK" who he described as being "a mixed bunch".

Some seemed "shocked at what had happened" and may have left the camp, arguing that it was not what they had come for.

Other British captors were described by him as being "vindictive".

Media playback is unsupported on your device Media caption Footage from Al Arabiya shows 48 Iranians kidnapped in Syria on Saturday, as the BBC's Jim Muir reports

The photojournalist said: "I think these are disenchanted young men from the UK who are now unified under this jihadist banner. I think they took out their angst on us."

Mr Oerlemans has already told Dutch media that some of the captors were British.

A Foreign Office spokesman said the government "takes very seriously any claims or reports that indicate there are British nationals amongst foreign fighters in Syria".

He said: "We are monitoring the situation as closely as possible. Clearly, the deteriorating security situation in Syria leaves a dangerous space for foreign fighters.

"The solution lies in securing robust international action to resolve the crisis."

Mr Cantlie and his Dutch colleague escaped when four members of the FSA intervened and gave the photographers an opportunity to flee the camp.

The pair ran amidst a hail of bullets which he likened to "a shooting gallery". Both were shot.

Mr Cantlie was shot in the arm and a bullet passed through Mr Oerlemans's thigh.