HOMS, Syria -- Tens of thousands of defiant Syrian protesters thronged Homs' streets Tuesday, calling for President Bashar Assad's execution shortly after his army pulled back its tanks and allowed Arab League monitors in for the first time to the city at the heart of the anti-government uprising.
The pullback was the first sign that the regime was complying with the league's plan to end the nine months of crackdowns on mostly unarmed and peaceful protesters.
Yet amateur video released by activists showed forces firing on protesters even while the monitors were in the city. One observer walked with an elderly man who pointed with his cane to a fresh pool of blood on the street. He said it had been shed by his son, killed a day earlier.
The man then called for the monitor to walk ahead to "see the blood of my second son" also killed in the onslaught.
"Where is justice? Where are the Arabs?" the old man shouted in pain.
Syrian tanks had heavily shelled Homs for days, residents and activists said, killing dozens even after Mr. Assad signed on last week to the Arab League plan. It demands that the government remove its security forces and heavy weapons from city streets, start talks with opposition leaders, and allow human rights workers and journalists into the country.
But a few hours before the arrival of the monitors, who began work Tuesday to ensure Syria complies with the league's plan, the army stopped the bombardment and pulled back some tanks.
The monitors were not joined by anyone from the government as they walked through the city, activists said, maintaining they did not stay long enough or venture deep enough into neighborhoods.
An activist identified only as Ali said the monitors did not see the field hospitals or the "hot spots."
"The observers failed today," he said.
Shortly after the tanks pulled back and stopped shelling, videos showed tens of thousands flooding the streets and marching defiantly in a funeral. They carried an open casket overhead with the exposed face of an 80-year-old man with a white beard.
"The people want to execute Bashar," chanted a group as they walked side by side with monitors through one of Homs' streets. "Long live the Free Syrian Army," they chanted, referring to the force of army defectors fighting Mr. Assad's troops.
The British-based activist group Syrian Observatory for Human Rights confirmed government forces fired on protesters while the monitors were in Homs and said at least two people were killed. About 60 monitors arrived in Syria Monday -- the first foreign observers Syria has allowed in since March, when the uprising began. The league said a team of 12 visited Homs.
After agreeing to the league's pullback plan Dec. 19, the regime intensified its crackdown; troops killed hundreds in the past week and Syria was condemned internationally for flouting the spirit of the agreement.
On Monday alone, security forces killed at least 42, mostly in Homs. Activists said security forces killed 16 Tuesday, including six in Homs.
Amateur videos show Homs residents pleading with the monitors for protection.
"We are unarmed people who are dying," shouted one man, shown in a video on YouTube Tuesday as he accosted some of the 50 observers in Syria. He asked them to go deeper into the city and pointed out pools of blood. In another video, a man asked, "Where is the world?"
Given the crackdown the past week, the opposition has viewed Syria's acceptance of the league's plan as a farce. Some accuse the group of 22 states of complicity in the killings. Activists say the regime is trying to buy time and forestall more international condemnation and sanctions.
"The Syrian government will cooperate symbolically enough in order not to completely alienate the Arab League," said Bilal Saab, a Middle East expert at the Monterey Institute of International Studies in California.
Mr. Assad's opponents doubt the Arab League can budge the autocratic leader at the head of one of the Middle East's most repressive regimes. Syria's top opposition leader, Burhan Ghalioun, called Sunday for the Arab League to bring the U.N. Security Council into the effort. The United Nations says more than 5,000 people have been killed since March in the political violence.