'Dozens killed' as gunmen open fire on protesters

There are reports that at least 39 protesters have been shot dead in Yemen after armed men opened fire on an anti-government demonstration in the capital, Sanaa.

At least 200 are said to have been wounded.

Reports say snipers positioned on roof-tops started firing at the crowds after Friday prayers, as security forces were attempting to move them from where they had gathered.

The BBC's Julian Worricker spoke to World Affairs Correspondent David Loyn and started by asking him if this was a significant peak in the escalating trouble.