BEIRUT -- Bowing to international pressure, including from long-time ally Russia, Syria on Monday accepted an Arab League plan to allow international monitors into the country to observe a situation that anti-government activists call a bloody crackdown on dissent.

Syria has agreed to implement a proposal signed last month by permitting an initial group of monitors to enter Syria within 72 hours and discussing plans for a total of 500 observers to operate across the country.

The agreement comes as Syria’s international isolation deepens amid attempts to suppress a nine-month uprising, which according to United Nations estimates has left at least 5,000 people dead. On Monday, activists reported that more than 70 soldiers were shot near the northwestern city of Idlib while trying to defect, though it was not possible to verify the figure.

President Obama and other Western leaders have called for Syrian President Bashar al-Assad to step down. Most Arab countries have pulled together in an unusual show of unity to condemn the actions of the Syrian authorities, and the Arab League last week proposed referring the Syrian issue to the U.N. security council.

Meanwhile, Russia, an ally that could previously be relied upon to veto any U.N. resolutions against Syria, last week advised Syrian leaders to implement the Arab League proposal, and suggested a Security Council resolution that refers to “disproportionate use of force,” by Assad’s troops.

Anti-government activists greet the news of the deal with “extreme skepticism,” said opposition member Yaser Tabbara, at a meeting in Tunisia of the Syrian National Council, an umbrella opposition group trying to position itself as a transitional ruling body.

Tabbara said that the Syrian government was well known for reneging on agreements, and the opposition group’s leader, Burhan Ghalioun, told reporters, “This is just a ploy. They have no intention of implementing any initiative.” He also called for Arab League and U.N. military action in Syria to establish safe zones.

“It’s a delaying maneuver,” said Salman Shaikh, of the Brookings Institution in Doha. “I wonder if the monitors will have access, be safe, and if the mission will carry on after the first monitors arrive.”

Shaikh added that Assad was unlikely to implement other parts of the Arab League agreement, which include withdrawing security forces from several parts of Syria. Even if forces were to withdraw from hotbeds of protest like the cities of Homs and Deraa, those cities would never again accept the rule of an Assad government, he said.

Andrew Tabler of the Washington Institute for Near East Policy, said Syria’s acceptance of the Arab League plan “would seem to be a victory for the opposition.” But the text of the protocol, he added, contained vague reference to security forces escorting monitors on observation missions. “We all know that allows the regime to stage things, and will debase the agreement,” he said.