UK to raise Syria 'chemical attacks' at UN, says Hague
The UK is to raise at the UN claims the Syrian authorities used chemical weapons and air strikes to kill hundreds on the outskirts of Damascus.
UK Foreign Secretary William Hague said there could be "no excuse" for the Syrian government not to allow UN monitors access to the suburbs of Zamalka, Arbeen and Ein Tarma.
The UK would pursue the issue at the UN Security Council, he added.
The Syrian army says the claims have been made up to cover up rebel losses.
But opposition activists say rockets with toxic agents were launched at the suburbs of the Ghouta region early on Wednesday, as part of a major bombardment of rebel forces.
Estimates of the number of people killed vary from 100 to 1,300 but have not been independently confirmed. It is not known how many were killed by shelling or by any exposure to toxic substances.
Mr Hague has been at an emergency meeting of EU foreign ministers, called to discuss political violence in Egypt.
It came as unverified footage on YouTube showed casualties, including children, suffering convulsions and breathing difficulties at makeshift hospitals in the suburbs of Damascus.
A team of UN inspectors is already in Syria to look at three other locations, including the northern town of Khan al-Assal, where some 26 people were killed in March.
But it is thought that they will need permission from the Syrian government to visit the new locations of Zamalka, Arbeen and Ein Tarma.
Speaking as he left the EU meeting, Mr Hague said: "The news from Syria has got worse in the last few hours... about what may have happened in chemical attacks and air strikes on civilians in an area near Damascus.
"There is no excuse for the Syrian regime not to provide access to the UN team that are in Damascus now to assess the use of chemical weapons. We are pursuing this with our partners at the Security Council.
"I think this is a very important matter for us to pursue over the coming days and hours."
Mr Hague said the UK could "pursue this very strongly at the Security Council" but added: "We have to bear in mind whenever we have tried to pass a strong resolution at the Security Council, we have met vetoes.
"That is a constraint on us. This is exactly the sort of matter which should be raised at the Security Council, so that is the way we are approaching it."
Labour leader Ed Miliband wrote on Twitter: "Truly horrific reports from Syria. Use of chemical weapons must be unequivocally condemned and UN must urgently investigate."
French President Francois Hollande has also called for UN inspectors to be allowed access to the area and said Britain and France would raise the issue at the UN.
In a statement, the army described the accusations of chemical weapons use as grave, and stressed the military's right to fight what it described as terrorism in Syria.
It accused the opposition of fabricating the accusations to divert attention from the huge losses its forces had suffered recently.
The Arab League echoed the call for the inspectors to go to the site, while Saudi Arabia called for the UN Security Council to convene immediately to discuss the matter.
EU foreign affairs head Catherine Ashton said the UN mission in Syria "must be allowed full and unhindered access to all sites".
"The EU reiterates that any use of chemical weapons, by any side in Syria, would be totally unacceptable," she said.
Experts believe that Syria has large undeclared stockpiles of mustard gas and sarin nerve agent.
Damascus has said the weapons, stored and secured by the armed forces, would never be used "inside Syria", but could be used against an external attack.