The Syrian military took its bombardment of the rebel-held Baba Amro district of Homs into a fourth week on Saturday as the Red Cross tried to evacuate more distressed civilians from the city.
At least 28 people were killed in Syria on Saturday, including nine in Homs, Syria's third city, according to the Syrian Observatory for Human Rights.
The state news agency SANA reported the funerals of 18 members of the security forces killed by "armed terrorist groups" in Homs, Deraa, Idlib and the Damascus countryside.
Deploring the outcome of an international "Friends of Syria" conference, opposition activists said the world had abandoned them to be killed by forces loyal to President Bashar al-Assad.
"They (foreign leaders) are still giving opportunities to this man who is killing us and has already killed thousands of people," said Nadir Husseini, an activist in Baba Amro.
The International Committee of the Red Cross (ICRC) said it had resumed negotiations with the Syrian authorities and the opposition to enable more civilians to be brought to safety.
Husseini said people in Baba Amro were suspicious of the ICRC's local partner, the Syrian Arab Red Crescent, and did not want to work with a group "under the control of the regime."
The ICRC denied this, saying the Syrian Red Crescent was an independent organization. "Their volunteers are risking their lives on a daily basis to help everyone with no exceptions," ICRC spokesman Hicham Hassan said in Geneva.
The ICRC said the Syrian Red Crescent had evacuated a total of 27 people from Baba Amro on Friday.
Four Western journalists, two of whom were wounded in an attack that killed two other foreign journalists on Wednesday have yet to be extracted from the shattered neighborhood.
Activists in Homs, a city of over 800,000 people located at the junction of highways leading from Damascus to Aleppo and the coast to the interior, described Friday's Friends of Syria meeting in Tunisia as a failure that had brought them no relief.
"I don't really care about the Tunis conference. All I care about is getting help for my family in the besieged areas," said Waleed Fares, contacted from Beirut. "The political calculations are not the same as the calculations for us revolutionaries."
A video uploaded by activists in Homs' Khalidiya district showed crowds at a funeral, shouting "We swear to God we will not be silent about our martyrs." In the background, clouds of smoke were rising from buildings that activists said had been hit by shell fire.
Civilians are enduring desperate conditions in Baba Amro.
"We have hundreds of wounded people crammed into houses," the activist Husseini said. "People are dying from lack of blood because we just don't have the capability of treating everyone."
The Tunis conference of Western, Arab and other countries was intended to ratchet up diplomatic pressure on Assad to end an almost year-long crackdown on opponents of his 11-year rule in which thousands of Syrians have been killed.
But to beleaguered Syrians the speeches seemed remote.
A doctor in the restive town of Zabadani said: "I'm really frightened that after all these efforts we will still end up like Hama in 1982, killed while the world waits and watches."
Assad's father crushed an armed Islamist uprising in Hama 30 years ago, killing many thousands of civilians and razing parts of the city with tanks and artillery in a three-week assault.
"The people of Zabadani resent what happened in Tunis," said the doctor, who asked not to be named. "We need them to arm the revolution. I don't understand what they are waiting for. Do they need to see half the people of Syria finished off first?"
Diplomacy is hamstrung because Russia and China, which did not attend the Tunisia meeting, oppose Security Council action and there is little appetite for military intervention in Syria.
"Iran's stance on Syria is to support reforms that benefit the Syrian people and oppose foreign intervention in that country's internal affairs," Iran's student news agency ISNA quoted Foreign Ministry spokesman Ramin Mehmanparast as saying.
Despite the bloodshed, Assad is staging a referendum on Sunday on a new constitution that he says will pave the way for a multi-party parliamentary election within three months.
The opposition has called for a boycott of the vote, deriding Assad's reform pledges and demanding that he step down.
Turkish Foreign Minister Ahmet Davutoglu questioned how the vote could take place in the midst of so much violence.
"On one hand you say you are holding a referendum and on the other you are attacking with tank fire on civilian areas. You still think the people will go to a referendum the next day in the same city?" he asked, at a news conference in Istanbul.
Davutoglu, whose country has turned strongly against its former friend since the Syrian revolt began in March, said Syria should accept an Arab League plan that calls on Assad to quit.
In Baba Amro, activist Husseini said he had "lost faith in everyone but God," but the uprising would go on regardless.
"The shelling is just like it was yesterday. We have had 22 days of this. The women and children are all hiding in basements," he said, his words tumbling out in anger.
"No one would dare try to flee the neighborhood, that is instant death. You'd have to get past snipers and soldiers. Then there is a trench that surrounds our neighborhood and a few others. Then you have to go past more troops."