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.
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.
At least 45 people were killed on Saturday, including 19 in Homs, according to the Syrian Observatory for Human Rights.
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 state news agency SANA reported the funerals of 21 members of the security forces killed by armed terrorist groups in Homs, Deraa, Idlib and the Damascus countryside.
At the conference in Tunis, Western and Gulf Arab nations mounted the biggest push in weeks to end the violence, escalating the pressure on Assad to step down.
But activists in Homs, a city of over 800,000 people at the junction of highways leading from Damascus to Aleppo and the coast to the interior, said the Tunisia meeting was a failure that brought no relief from the bombardment.
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 International Committee of the Red Cross (ICRC) said it was negotiating with the Syrian authorities and the opposition to enable more civilians to be brought to safety.
But 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 organisation. 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 neighbourhood.
A video uploaded by activists showed smoke curling up from buildings hit by rocket fire in Homs' Khalidiya district. Nearby, crowds carried six bodies wrapped in white shrouds shouting We swear to God we will not be silent about our martyrs.
Civilians are enduring desperate conditions in Baba Amro.
We have hundreds of wounded people crammed into houses. People die from blood loss. We just aren't capable of treating everyone, said Husseini, his words tumbling out in anger.
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.
I don't understand what they are waiting for. Do they need to see half the people of Syria finished off first? said a doctor speaking anonymously from the rebellious town of Zabadani, which the army regained control of last month by shelling and surrounding the area.
The people of Zabadani resent what happened in Tunis, he said, referring to the conference. We need them to arm the revolution.
Pro-government newspapers criticised the conference as a conspiracy. At the conference, the Saudi foreign minister said arming rebels was an excellent idea and walked out of the Tunis meeting, arguing there was a lack of action.
An opinion piece in al-Thawra, seen as a voice for the government, blamed Riyadh for rising bloodshed in Syria.
It (Saudi Arabia) insolently announced its support for these terrorists and be a direct partner in shedding the bloods of more Syrians, the editorial said.
The opposition has called for a boycott of the referendum, 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 said the uprising would go on and that escape was impossible.
No one would dare try to flee the neighbourhood, that is instant death. You'd have to get past snipers and soldiers. Then there is a trench that surrounds our neighbourhood and a few others. Then you have to go past more troops.
(Additional reporting by Dominic Evans in Beirut, Stephanie Nebehay in Geneva, Seda Sezer in Istanbul and Mitra Amiri in Tehran; Writing by Alistair Lyon; Editing by Kevin Liffey)
$INS01; Line LNY Insave:- TI line name (Map report)