The Syrian government has allowed UN inspectors to investigate allegations of a suspected chemical weapon attack near Damascus.
The team is to begin work on Monday. Activists say Syrian forces killed more than 300 people in several suburbs east and west of the capital on Wednesday.
State media reported that chemical agents were found in tunnels used by rebel fighters, and also that soldiers suffered “suffocation” in fighting around the suburb of Jobar.
State TV is meanwhile reporting that the governor of the central district of Hama, Anas Abdul-Razzaq Naem, has been killed in a car bomb attack.
The Syrian foreign ministry statement broadcast on state television said an agreement to allow UN chemical weapons experts to “investigate allegations of chemical weapons use in Damascus province” had been concluded on Sunday with the UN’s disarmament chief, Angela Kane.
The agreement was “effective immediately”, the statement added.
A spokesperson for UN Secretary General Ban Ki-moon subsequently announced that the inspectors were “preparing to conduct on-site fact-finding activities”, starting on Monday. A ceasefire will be observed at the affected locations, the statement said.
Russia, a key ally of Syria, welcomed the decision to allow the inspectors in but warned the West against pre-empting the results.
Medecins Sans Frontieres (MSF) said on Saturday that three hospitals it supports in the Damascus area had treated about 3,600 patients with “neurotoxic symptoms” early on Wednesday morning, of whom 355 died.
While MSF said it could not “scientifically confirm” the use of chemical weapons, staff at the hospitals described a large number of patients arriving in the space of less than three hours with symptoms including convulsions, pinpoint pupils and breathing problems.
UK’s PM David Cameron has discussed the situation in a telephone call with President Francois Hollande of France.
David Cameron agreed a similar response in a telephone conversation with US President Barack Obama on Saturday evening.
Later, Syria’s Information Minister, Omran Zoabi, warned that US military action in Syria would not be a “walk in the park”.
“If the US leads a military intervention, this will have dangerous consequences. It will bring chaos and the region will burn,” he said.
A year ago, President Barack Obama said that any attempt by Syria to use its chemical weapons would be a “red line” for the US, and change his administration’s “calculus” in the region.