The British Foreign Office responded to the reported massacre in Houla, Syria, by summoning the Syrian chargé d'affaires to a meeting on Monday.

Sir Geoffrey Adams, the political director of the Foreign Office, made clear to the Syrian diplomat the UK's condemnation of the appalling massacre

Reports confirmed 108 people, including 49 children and 34 women, were killed in the massacre on 25 May.

Adams described this as a sickening and evil crime. Foreign Secretary William Hague has said that his government is making urgent consultations with its international partners to take action in response to the massacre. The Syrian regime denies any responsibility for the violence.

In a statement after meeting with the Syrian diplomat, Adams said that "an urgent international investigation should be carried out into the massacre, and those responsible for acts of violence should be identified and held accountable."

He added that unless the Syrian regime ceased all military operations immediately and implemented Kofi Annan's six-point peace plan in full, the international community would take further quick and robust action in response.

"The responsibility to end the violence lies squarely with [Syrian president Bashar] Al-Assad and those around him," Adams said in a statement.

London has been calling Assad to step down to clear the way for reforms in the country.

"The spiralling conflict and worsening sectarian violence was a product of the regime's brutal response to dissent," the statement said.