US-Russia brokered Syria truce 'to start on weekend'

The United States and Russia have agreed on a plan that would create a ceasefire in Syria starting Saturday.

Officials said on Monday that the two sides have agreed on the terms and conditions for the "cessation of hostilities" in attempts to prevent the gaining of new ground.

However, the truce excludes the Islamic State group and the al-Qaeda-linked Nusra Front, as well as any other group deemed a "terrorist organisation" by the Security Council.

Talks of the truce come as over 170 were killed in a string of bomb attacks in the Syrian cities of Damascus and Homs on Sunday, attacks claimed by the Islamic State group.

Since the conflict began in March 2011, it has claimed more than 260,000 lives and has left 13.5 million people inside Syria in desperate need of humanitarian assistance.

UN special envoy for Syria, Staffan de Mistura, said this week would be "crucial" for efforts to help end the fighting, but he made no comment on the timing of the truce.

The truce excludes the Islamic State group and the al-Qaeda-linked Nusra Front

Monday's agreement calls on all parties to halt fire and any attempts to capture areas. However, if any attacks occur, response from agreeing parties will be proportionate.

It also calls for the release of prisoners in Syria and to lift blockades as soon as possible.

Russia and US will cooperate over determining which groups are in control of which areas.

The announcement caps weeks of diplomacy, intensified in the past few days, with aims to reach a temporary truce that would allow the parties to return to the negotiating table in Geneva.

A first round of indirect talks collapsed rapidly last month after the government launched a massive offensive backed by Russian airstrikes in the northern province of Aleppo, near the Turkish border.

Suheir Atassi from the Syrian Higher Negotiations Committee [HNC] confirmed that the group received the details of the agreement between the opposition and the regime.

She said that the Syrian opposition remains cautious but will start to work towards the cessation of fire by Friday leading onto Saturday.

But Syrian official, Omar Osso, says a temporary truce will not stop the government and its allies from striking the Islamic State group, an al-Qaida affiliate "and other terrorist groups".

Osso, a member of parliament who was on the Syrian negotiating team in Geneva earlier this month, said a truce might be "relatively successful" in some areas but said the government has the right to continue to combat terrorism.

He said he was "not optimistic that clashes will stop because we are dealing with criminals who have hundreds of state sponsors" and various loyalties.

Over the weekend, Syrian President Bashar al-Assad said his government was ready to take part in a truce as long as it is not used by militants to reinforce their positions.

"We announced that we're ready," Assad told Spain's El Pais newspaper on Sunday. "It's about preventing other countries, especially Turkey, from sending more recruits, more terrorists, more armaments, or any kind of logistical support to those terrorists."