Scores of people have been killed in Homs, including two foreign journalists, according to activists, as government forces continue to shell the central Syrian city.
More than 60 bodies, of both civilians and armed fighters, were recovered on Wednesday from the neighbourhood of Bab Amr after an afternoon bombardment, activists said.
Among those killed were Marie Colvin, a US reporter working for the UK's Sunday Times newspaper, and French photographer Remi Ochlik working for Paris Match magazine.
Omar Shakir, an activist in Bab Amr, told Al Jazeera that the Western reporters were killed after a building, used by activists as a media centre, was shelled.
Nine people were reportedly killed in that attack and Sunday Times photographer Paul Conroy was injured, along with two other reporters.
The barrages marked an intensification of a nearly three-week offensive to crush resistance in Homs, one of the focal points of a nationwide uprising against President Bashar al-Assad's 11-year rule and its ferocity has caused international outrage.
"Helicopters flew reconnaissance overhead then the bombardment started," Abu Abei, an activist in Homs, told the Reuters news agency.
Videos uploaded by opposition activists showed smashed buildings, deserted streets, and doctors treating wounded civilians in primitive conditions in Bab Amr.
A few hours after the death of Colvin, Sunday Times editor John Witherow said: "Marie was an extraordinary figure in the life of the Sunday Times, driven by a passion to cover wars in the belief that what she did mattered."
"She believed profoundly that reporting could curtail the excesses of brutal regimes and make the international community take notice," he said in a statement.
Witherow said the newspaper was doing what it could to get Conroy to safety and to recover Colvin's body.
Adnan Mahmoud, the Syrian information minister, told state news agency SANA that there was no record of Colvin or Ochlik entering the country, and that authorities in Homs had been "asked to look for the whereabouts of these journalists".
A foreign ministry statement released on Thursday rejected "statements holding Syria responsible for the deaths of
journalists who sneaked into its territory at their own risk".
In a phone interview with British state broadcaster BBC on Tuesday, Colvin described the situation in the area as "absolutely sickening".
She said she had witnessed the death of a two-year-old boy after he was hit by shrapnel, and said there was a "constant stream of civilians" in the field clinic she visited.
"No one here can understand how the international community can let this happen," she said.
Colvin was an experienced foreign correspondent and was named foreign reporter of the year by the British Press Awards in 2001. She lost an eye to a grenade while working in Sri Lanka.
Ochlik had photographed the Tunisian and Egyptian revolutions as well as the war in Libya. His work was published in Le Monde magazine, Time magazine and The Wall Street Journal, among other outlets.
The attack on journalists drew international condemnation, with the US saying the incident was "another example of the shameless brutality of the Assad regime".
France demanded access to the victims of the attack and summoned Syria's ambassador to Paris.
"I am asking the Syrian government to immediately stop attacks and respect its humanitarian obligations," Alain Juppe, the French foreign minister said.
"I have asked our embassy in Damascus to require the Syrian authorities provide secure medical access to assist the victims with the support of the International Committee of the Red Cross."
Hours after the bombardment that killed the journalists, Syria's information ministry said journalists illegally inside the country should report to the government.
"The ministry asks all foreign journalists that have entered Syria illegally to go to the nearest centre for immigration and passports to resolve the situation according to the laws in force," the ministry said in a statement on Syria TV.
A day earlier, Rami al-Sayyed, a Syrian citizen journalist who provided live footage on the Internet from Bab Amr, was killed when a rocket hit a car in which he was travelling, Hadi al-Abdullah, a Homs-based activist, said.
Shortage of medicine
Abdallah described the humanitarian situation in Bab Amr as "catastrophic" on Wednesday morning.
"Water has been cut off from Bab Amr for 18 days," he told Al Jazeera by phone. "There's no electricity, cooking oil or even bread. Many people are literally on the brink of starvation.
"People have fled their homes in fear of being bombed. They took refuge in a mosque, and there they were bombed too."
The Homs Revolutionary Council, an opposition activists' network, reported a shortage of medicine, and said a large number of killed civilians were buried under the rubble of buildings damaged in the shelling.
In-depth coverage of escalating violence across Syria
In the nearby Inshaat neighbourhood, the group said security forces, supported by the army and by armoured vehicles, had carried out house raids and arrests.
Bab Amr is a stronghold of the armed opposition, but activists say most of those killed in the assault on the area were civilians.
The Local Co-ordination Committees, an umbrella organisation of opposition groups, says about 3,000 people have been killed in Homs province since the uprising began in March last year. The activist network says more than 8,000 people have been killed nationwide.
Official media said government forces were targeting "armed terrorist groups who have been terrifying citizens and attacking security forces and robbing public and private property".
State-run news agency SANA cited residents of Homs saying food and services were available and that reports claiming the opposite were "lies".
The opposition Syrian National Council (SNC) said on Wednesday it was coming to the view that military intervention was the only solution to the nearly year-old crisis in the country.
"We are really close to seeing this military intervention as the only solution. There are two evils, military intervention or protracted civil war," Basma Kodmani, an SNC spokeswoman, announced in Paris.
Kodmani said the SNC was also proposing that Russia, an ally of Syria, help persuade Damascus to guarantee safe passage to humanitarian convoys ferrying aid to civilians. She said the SNC proposed setting up corridors from Lebanon to Homs, from Turkey to Idlib and from Jordan to Deraa.
Russia's foreign ministry spokesman said Russia was supporting the International Committee of the Red Cross's call for a daily two-hour ceasefire to provide aid to the population of Syria.
Alexander Lukashevich said Russia was using its contacts with both the Syrian government and the opposition to help settle humanitarian issues.