Media playback is unsupported on your device Media caption William Hague: "This will go down in history as a criminal regime - the Assad regime"

The UK is to officially recognise the Syrian National Council as a "legitimate representative" of the country, William Hague has announced.

The foreign secretary said the UK was to "intensify" links with the council - Syria's largest opposition group.

Mr Hague also said President Bashar Assad's regime had "forfeited the right to lead" by "miring itself in the blood of innocent people."

He was speaking at the international Friends of Syria conference in Tunisia.

Activists say more than 7,000 people have died in the 11-month uprising - more than 90 on Thursday alone - and concern is growing over the humanitarian situation, particularly in the besieged city of Homs.

Mr Hague said: "Today we must show that we will not abandon the Syrian people in their darkest hour."

He called for international humanitarian assistance and said the UK was talking to those who had fled the country about what crimes were happening there.

"Those responsible for the murder of entire families, the shelling of homes, the execution of detainees, the cleansing of political opponents and the torture and rape of women and children must be held to account," he said.

Image caption Around 70 nations are attending the Tunisia conference

Mr Hague will continue to meet and engage with representatives from other Syrian opposition groups but it is believed the status bestowed on the Syrian National Council will give it more responsibility to help end the situation in the troubled country.

"Syria should not belong to one family, to one coterie, or to one party. It belongs to all the people of Syria equally, in all their religious and ethnic diversity," he added.

Around 70 nations, including the US, UK, France and Turkey, are attending the conference, organised by the Arab League.

Both Russia and China - which have vetoed attempts at a UN Security Council resolution against Syria - refused to attend the Tunis conference.

Those who back the Syrian regime from now on will find themselves in an even more isolated and indefensible minority William Hague, UK foreign secretary

But Mr Hague said: "Those who back the Syrian regime from now on will find themselves in an even more isolated and indefensible minority."

He called for a "diplomatic and economic stranglehold on the Assad regime" and said all oil purchases from Syria and investment in the country had to be stopped.

Arms embargo

"I call on all nations here to adopt without delay concrete sanctions that will have an effect on the regime, and I am confident that at the European Union we will add to them in the coming days," he said.

The Syrian National Council had suggested rebel fighters could be supported with weapons.

It said countries should be allowed to supply it with arms if Damascus refused to bow to outside pressure.

But Mr Hague said that the European Union continued to have an arms embargo on Syria.

Syrian state TV said the conference was a meeting of "symbols of colonialism" and described those attending as "historic enemies of the Arabs".

Meanwhile the Red Cross has begun moving women and children from part of the besieged Syrian city of Homs, officials say.

Syrian Arab Red Crescent ambulances are moving them from the suburb of Baba Amr, which has been under heavy attack, after negotiations earlier in the day.

Injured journalists are among those awaiting rescue, but the Red Cross says it wants to evacuate all those in need.

Sunday Times reporter Marie Colvin, an American, and French photographer Remi Ochlik died in shelling by Syria's government forces on Wednesday. At least two other foreign journalists - British freelance photographer Paul Conroy, and Edith Bouvier of the French newspaper, Le Figaro - were injured and are said to have been taken to a field clinic in Baba Amr.

The Red Cross says it is in talks with both the Syrian authorities and the opposition about bringing the injured to safety.