(CNN) -- Syrian opposition activists spoke Tuesday of being past the point of no return in their struggle against the Assad regime, which stepped up its siege on the city of Homs and reportedly launched fresh attacks all over the country.

At least 49 people were killed, according to the opposition Local Coordination Committees of Syria. The deaths included three defected Syrian soldiers, the group said.

Deaths took place in Idlib, Homs, Daraa, Aleppo, Deir Ezzor, Hama, Damascus, the Damascus suburbs and Latakia, the group said.

Fear and horror paralyzed residents of Homs, with snipers preventing anyone from moving and heavy shelling blasting through the air, opposition activists said.

"The snipers are even targeting those who intend to get bread from the bakeries," said one activist, who uses the pseudonym Abu Omar.

"They are shelling randomly -- why, I don't know," said another activist, identified only as Omar for security reasons. "There is no place here in this city that is a safe house or shelter or a basement. You have to be lucky to stay safe."

Tuesday's shelling was among the heaviest in the past five days, according to the opposition Syrian Observatory for Human Rights.

Child rescued from crossfire in Syria

Increased intelligence activity in Syria

UN to vote on new Syria resolution

Syrians 'dismissive of diplomacy'

While United Nations diplomats slammed the Syrian regime for the country's mounting bloodshed, residents wondered what lay ahead.

"Everyone we've been talking to ... believes that the country is heading toward, or already is in, a full-blown war, and recovering from that is going to be incredibly challenging," said CNN's Arwa Damon, who reported from inside Syria Tuesday.

She spoke from an opposition safe house, describing a near constant flow of people and information. CNN is not disclosing her exact location because of concerns for her safety.

Logistical challenges are extremely challenging, Damon reported. Living rooms are serving as makeshift triage clinics.

"Villagers have tried to gather medical supplies and blood to move them into these hard-hit areas and for days have been unable to do so" because of the government crackdown, she said.

Members of the opposition believe it is a fight to the death and, if they fail, the government will kill them, Damon reported. Many, she said, would even be willing to accept assistance from Israel, a sworn enemy.

Her reports came a day after the U.N. high commissioner for human rights denounced the Syrian government's "ongoing onslaught" against its citizens. Navi Pillay spoke before the U.N. General Assembly, which could issue a formal condemnation of the Syrian regime.

"The nature and scale of abuses committed by Syrian forces indicates that crimes against humanity are likely to have been committed since March 2011," Pillay said.

Syria posted a banner on state TV Tuesday saying its foreign affairs ministry "absolutely rejects all the new allegations in the new report by the human rights high commissioner."

Syria also rejected decisions made over the weekend at a meeting of the Arab League. The league proposed a joint U.N.-Arab peacekeeping force and urged member states to provide political and financial support to the Syrian opposition and to cut ties with Damascus.

SANA quoted "an official source" Tuesday as calling the league meetings a "blatant interference in (Syria's) internal affairs and an encroachment on its national sovereignty."

The Syrian government said on state-run news agency SANA that 13 "army and law enforcement martyrs" were buried Tuesday. "The martyrs were killed in the line of duty by armed terrorists groups in Damascus Countryside, Homs and Idlib."

SANA also reported that large crowds gathered in Latakia in support of the government's "reform process, rejecting foreign interference," and denouncing "terrorist bombings" that took place last week in Aleppo.

Two government buildings were bombed last week in the city, killing 28 people, Syrian officials said. Syria has cited the incident to argue that terrorist groups, specifically al Qaeda, are active in the country.

A U.N. General Assembly draft resolution that would condemn Syrian human rights violations has been discussed by diplomats but not formally introduced. It was unclear when the draft would be presented and when diplomats would vote on it.

The vote would not be binding, but would be the strongest U.N. statement yet on the violence. Russia and China vetoed previous attempts by the U.N. Security Council to condemn Syria for the crackdown.

The draft resolution calls on Syria to end human rights violations and attacks against civilians immediately, and condemns "all violence, irrespective of where it comes from."

U.S. President Barack Obama and Vice President Joe Biden welcomed Chinese Vice President Xi Jinping, that nation's presumptive premier, to the White House. Speaking of Syria and the recent U.N. debate, Biden said at a news conference, "While the United States and China ... will not always see eye to eye -- it is a sign of the strength and maturity of our relationship that we can be candid about our differences as we have been."

Victoria Nuland, a U.S. State Department spokeswoman, said Tuesday that increasing pressure and sanctions on the Assad regime was crucial.

European Union diplomats told CNN they expect new EU sanctions on Syria by February 27, targeting the Syrian Central Bank and imposing a ban on exports of precious metals and phosphates.

More than 700 people have been killed over the past 10 days in Syria -- mostly in Homs, the Local Coordination Committees said.

A video posted Friday on YouTube shows a child running down the middle of a street while gunfire is heard. A man runs into the street to pick up the child and take him to safety near a building. The man runs back into the street apparently to get the child's shoe. Voices can be heard chanting, "God is great," and "We have no one but you, God, for help."

A voice on the recording says it is in the al-Balad neighborhood of Daraa.

Another video on YouTube shows tanks and civilians standing next to them in a Damascus suburb. An opposition activist has said government forces are using detained civilians as human shields, placing them on tanks to prevent the opposition Free Syrian Army from fighting back.

CNN cannot independently confirm details of the events in Syria because the government has severely limited the access of international journalists.

Damon said every person she interviewed had a horror story to tell.

"One man we met, he had four members of his family executed as government forces, he said, were raiding their village," she said.

She said some members of the opposition believe the regime will fall someday, but it's uncertain how many more lives will be lost before that happens.

"If there is military intervention, then yes, there will be a lot of bloodshed. But it's going to be over a lot quicker," one young activist said. "If there isn't military intervention, there is going to be even more bloodshed, and it's going to take a lot longer to bring down the regime."