Syria conflict: Temporary truce comes into effect

A landmark temporary truce has come into effect in Syria.

If the "cessation of hostilities" holds it would be the first time a pause in Syria's five-year civil war has been negotiated by world powers.

In the run-up to the midnight (22:00 GMT) deadline, US President Barack Obama warned the Syrian government and Russia "the world will be watching".

Russian jets were reported to have intensified attacks on Syrian rebel positions on Friday.

Meanwhile, the UN special envoy for Syria Staffan de Mistura has announced that peace talks will resume on 7 March if the truce "largely holds".

Mr de Mistura said he had no doubt "there will be no shortage of attempts to undermine this process".

"This will remain a complicated, painstaking process," he told the UN Security Council via videoconference from Geneva. 

But he added: "Nothing is impossible, especially at this moment."

Previous talks in Geneva collapsed in early February after making no progress.

The UN Security Council also unanimously adopted a resolution drafted by the US and Russia that endorsed the truce agreement.

The cessation of fighting involves government and rebel forces - but not the so-called Islamic State (IS) and the al-Qaeda-linked Nusra Front. On Friday, Nusra Front urged its supporters to intensify attacks against President Bashar al-Assad and his allies.

Almost 100 rebel factions have agreed to respect the truce, Syrian opposition umbrella group the High Negotiations Committee (HNC) said.

The HNC warned the Syrian government and its allies not to use the "proposed text to continue the hostile operations against the opposition factions under the excuse of fighting terrorism".

Russian President Vladimir Putin said his forces were targeting IS, Nusra Front and other extremist groups designated as legitimate targets by the UN Security Council.

President Obama said the success of the cessation would depend on whether warring parties including the Syrian government, Russia and their allies lived up to their commitments.

Attacks needed to end, he said, and humanitarian aid had to be allowed through to desperate civilians.

"The coming days will be critical and the world will be watching," he added.

More than 250,000 Syrians have been killed in Syria's civil war and millions more have been forced from their homes.