The city of Zabadani was retaken by Syrian government forces on Monday, though fighting with members of the Free Syrian Army remains fierce. Residents of the south-western city told Avaaz they feared a massacre. In Homs, shelling continues for the tenth straight day. Activists said the bombardment was the worst it has been in days.

Following an Arab League call for a joint Arab League-United Nations peacekeeping mission to the country, US secretary of state Hillary Clinton said Syrian president Bashar al-Assad would have to agree to foreign troops.

In Washington, President Barack Obama will hold talks Tuesday with Chinese vice-president Xi Jinping. The tête-à-tête has been billed as a profile-building meet-and-greet for the 58-year-old Xi, who is expected to to take over the ruling Communist party this year. Few substantive exchanges are expected but Obama is under pressure to address China's fiscal and trade polices, and Xi has already voiced displeasure over a US defence build-up in south-east Asia.

Meanwhile, in Tibet, another young monk set himself on fire to protest at China's security crackdown. He is one of at least 20 Tibetan activists to self-immolate over the past year. Four pro-Tibetan demonstrators were arrested in Washington ahead of Tuesday's meeting.

In Europe, ratings agency continued to bluster over the eurozone crisis. With all eyes on riots in Greece, Moody's threatened to knock the UK, France and Austria from their AAA perch. The agency actually downgraded six other EU countries, including Italy and Portugal. The ratings agencies have been hounding governments for months, and despite their past failures, the markets always respond. The euro and the pound fell after Moody's announcement.