Syria signed an Arab League initiative Monday that will allow Arab observers into the country, on a day when activists said more than 100 people were killed, making it one of the bloodiest days in the nine-month uprising.

Activists reported up to 70 army defectors were killed by security forces who fired at them as they were deserting their military posts near the Turkish border. At least 30 other people died in other incidents across the country, the activists said.

Syria has placed severe restrictions on journalists, and the reports by the British-based Syrian Observatory for Human Rights and the Syrian Revolution General Commission activist group could not be independently confirmed.

The signing at the Arab League headquarters in Cairo followed increasing world pressure on Syria alongside a wave of armed clashes between Syria's military and defectors from the army, raising fears of an imminent civil war.

The regime's acceptance of observers after weeks of delays came after a warning from Arab leaders that they would turn to the UN Security Council for action to try to end President Bashar Assad's crackdown that the UN says has killed at least 5,000 people.

The UN General Assembly on Monday condemned human rights violations by Assad's government, calling for an immediate end to violence and implementation of the Arab League plan "without further delay." The vote on the nonbinding resolution was 133-11 with 43 abstentions.

By signing, the Syrian regime stands to gain more time and to avert — for now at least — the possibility of wider international involvement in the crisis. But critics were skeptic the regime would actually allow the observers full, unrestricted access to trouble spots and said it was likely a delaying tactic.

Opposition says signed deal 'worthless'

Burhan Ghalioun, the leader of Syria's main opposition group the Syrian National Council, accused the Assad regime of lying and said the signing was "worthless" in light of the brutal crackdown under way daily in Syria.

"The Syrian regime is maneuvering and wants to buy time," he said in Tunisia, where the group has been holding a three-day conference aimed at unifying Syria's fragmented opposition.

Ghalioun called for Arab military intervention to protect Syrian civilians and the creation of humanitarian corridors to deliver aid.

Syrian Foreign Minister Walid al-Moallem rejected accusations of Syrian stalling tactics and said the delay was caused by the Arab League's refusal until now to accept amendments Syria requested. He did not say what they were.

"The signing of the protocol is the beginning of cooperation between us and the Arab League, and we will welcome the Arab League observers," he told reporters in Damascus.

He said that the observers will have a one-month mandate that can be extended by another month if both sides agree. The observers will be "free" in their movements and "under the protection of the Syrian government," he said, but will not be allowed to visit sensitive military sites.

The Arab League's plan calls for removing Syrian forces and heavy weapons from city streets, starting talks with opposition leaders and allowing human rights workers and journalists into the country, along with Arab League observers. Despite agreeing last month to the initiative, Syria then posed conditions that the Arab League said made implementation impossible.

A Syrian-based anti-regime activist who identifies himself as Abu Hamza said the Syrian regime "has signed something it cannot implement." He said if the government withdraws the military from the streets, mass demonstrations will take pace throughout the country.

"This will automatically lead to the downfall of the regime," Abu Hamza said, declining to give his real name for fear of retribution.

Clashes with security forces in central and northern Syria

In Cairo, Arab League chief Nabil Elaraby said a mission headed by one of his assistants will head to Syria "within a day or two." He said it will include legal, administrative, financial and human rights experts to discuss the makeup of the observer teams.

"Each group of observers will contain 10 or more people and will go to different places," said Elaraby. He said Syrian opposition groups will outline their views at the Arab League soon, and then the Syrian government will be invited to give its input about reforms.

As the agreement was signed, security forces shot and killed at least 20 people in the southern province of Daraa, in central Syria's Homs region and in the country's north. One person was killed when security forces opened fire on thousands of mourners in Damascus' central neighborhood of Midan. The mourners were attending the funeral of a child who was gunned down by security forces a day earlier, according to the British-based Observatory.

Another activist group said Monday's death toll throughout Syria was 31.