The United Nations Supervision Mission in Syria announces it suspended its all activities on Saturday, due to the mounting armed violence and escalation in the country over the past 10 days. Activists say more than 14,400 people have been killed since the uprising erupted, including 3,353 since April 12 when international envoy Kofi Annan's ceasefire plan came into effect.
Here is an time line for UN efforts to end the violence in Syrian since protests erupted against the regime of Bashar al-Assad in mid-March 2011.
- 27: The UN Security Council's 15 powers clash over the crackdown on opposition protests, with Russia warning the West that "outside interference" could spark civil war.
- 14: Experts from the United Nations High Commissioner for Refugees (UNHCR) arrive at the Syria-Turkey border to "investigate the abuses" in Syria.
- 3: The UN Security Council condemns attacks on Syrian civilians and calls in its first declaration on the crackdown for those responsible to be held "accountable."
- 16: The UN General Assembly demands an immediate halt to the crackdown, in a strongly worded resolution put forward by Egypt and other Arab states adopted by a 137-12 vote, with China, Russia and Iran opposing the text.
- 7: The UN's humanitarian chief visits Syria to try to secure aid for battered protest cities, including Baba Amr, a rebel district in the flashpoint city of Homs.
- 10-11: UN and Arab League envoy Kofi Annan presents a plan to Assad for ending the bloodshed.
- 21: The UN Security Council demands that Syria "immediately" implement Annan's plan and issues a veiled warning of international action.
- 12: A ceasefire comes into effect in line with an ultimatum set by Annan, but it is systematically breached daily.
- 14: The UN Security Council unanimously passes its first ever resolution on the Syria crisis, allowing for an advance party of 30 unarmed ceasefire monitors.
- 21: The Security Council unanimously passes a resolution allowing a 300-strong ceasefire monitoring mission for an initial 90 days.
- 9: A blast hits troops escorting UN observers in the restive town of Daraa.
- 24: The Syrian army and security forces have been responsible for the majority of serious rights abuses, UN-appointed investigators say.
- 25: At least 108 people, including around 50 children, killed in a massacre at Houla in central Syria, sparking international outrage.
- 27: The UN Security Council condemns Damascus over the Houla massacre, saying the attacks "involved a series of government artillery and tank shellings on a residential neighbourhood."
- 28: Annan says he is "shocked" at the "tragic events" in Houla as he arrives in Damascus.
- 6: At least 55 people killed in the village of Al-Kubeir where UN observers are shot the next day while trying to reach it.
- 7: Annan confirms discussions on establishing an international contact group on Syria.
- 8: UN observers reach Al-Kubeir.
- 12: UN observers trying to reach the besieged town of Al-Haffe say they were fired upon after being driven back by an angry crowd hurling stones and metal rods at their vehicles.
- 13: France says it will propose that the UN Security Council resort to Chapter VII of the UN Charter for making "obligatory" the provisions of Annan's peace plan.
- 15: The UN observer mission head, General Robert Mood, accuses both sides in the Syrian conflict of hampering its mission and acknowledges its limitations in the face of escalating violence.
- 16: Mood suspends the work of the UN observers.