* ICRC aid kept out of Baba Amro, fears grow for civilians
* Bodies of two journalists handed to Western diplomats
* Syrian state media report suicide bombing in Deraa (Adds Turkish, Human Rights Watch comment, killings in north, east Syria)
By Khaled Yacoub Oweis and Mohammed Abbas
BEIRUT, March 3 (Reuters) - Syrian forces bombarded parts of the shattered city of Homs on Saturday and for a second day blocked Red Cross aid meant for civilians stranded for weeks without food and fuel in the former rebel stronghold, activists and aid workers said.
The renewed government assault came a day after U.N. Secretary-General Ban Ki-moon said he had received "grisly reports" that President Bashar al-Assad's troops were executing, imprisoning and torturing people in Syria's third largest city.
"In an act of pure revenge, Assad's army has been firing mortar rounds and ... machine guns since this morning at Jobar," said the Syrian Network for Human Rights, naming a neighbourhood adjacent to Baba Amro, from which Free Syrian Army rebels pulled out this week after almost a month of siege and shelling.
"We have no immediate reports of casualties because of the difficulty of communications," the campaign group said in a statement.
Syria's government says it is fighting foreign-backed "armed terrorists" which it blames for killing more than 2,000 soldiers and police. The United Nations says Syrian security forces have killed more than 7,500 civilians since the revolt against Assad's rule began in March last year.
Concern was mounting for civilians in freezing conditions in Baba Amro, where International Committee of the Red Cross (ICRC) trucks were still being held up by Assad's forces. The ICRC said the trucks would spend a second night in Homs and await premission to enter Baba Amro.
"The ICRC and Syrian Arab Red Crescent did not enter Baba Amro today. Our negotiations with Syrian authorities continue in order to enter and help as many people as possible," ICRC spokesman Hicham Hassan told Reuters in Geneva.
Anti-government activists said they feared troops wanted to prevent the ICRC witnessing a reported massacre of rebels in Baba Amro, which had become a symbol of a year-long uprising.
A Damascus-based ICRC spokesman said Syrian authorities had given the convoy permission to enter but that government forces on the ground had stopped the trucks because of what they said were unsafe conditions, including "mines and booby traps".
"There has been fighting there for at least a month. The situation cannot be good. They will need food, it's cold, they will need blankets. And there are injured there that need to be evacuated immediately," Saleh Dabbakeh told Reuters.
Syrian state television broadcast interviews with unnamed civilians in what it said was the stricken district, against a backdrop of empty streets, some with heavy conflict damage.
"Anyone who went out on the street was kidnapped or slaughtered. We called for the army to come in. God bless the army, they saved us from the armed terrorist gangs," said one interviewee, referring to the Free Syrian Army (FSA) rebels.
Elsewhere in Syria, anti-Assad activists reported mass arrests and the killing of six soldiers, while the government's SANA news agency reported a suicide car bombing in the southern town of Deraa, a blast activists denied was a suicide attack.
In a sign of unrest spreading, activists also said seven people had been killed in Syria's north, and that three had been shot dead in east Syria's Deir al-Zor when troops opened fire on a funeral for two killed in a crackdown on democracy protests.
Colonel Malik Kurdy, deputy of FSA chief Colonel Riad al-Asaad said rebel fighters had seized an arms cache in a battle in countryside north of Damascus and killed and wounded some 100 Syrian troops, but added that the report was preliminary.
Rights group Human Rights Watch distributed satellite images of Baba Amro that it said showed widespread destruction.
"The bombardment has severely restricted movement and relief efforts and deprived thousands of civilians of the ability to access the most basic commodities," it said in a statement.
In unusually tough remarks to the 193-member U.N. General Assembly on Friday, Ban explicitly blamed Damascus for the fate of civilians in the conflict.
"The brutal fighting has trapped civilians in their homes, without food, heat or electricity or medical care, without any chance of evacuating the wounded or burying the dead. People have been reduced to melting snow for drinking water," he said.
"This atrocious assault is all the more appalling for having been waged by the government itself, systematically attacking its own people."
Syrian U.N. Ambassador Bashar Ja'afari, said Ban's comments included "extremely virulent rhetoric which confines itself to slandering a government based on reports, opinions or hearsay."
SANA said the Deraa bomber killed three people and wounded 20 others, while residents said seven people had been killed.
Rami Abdelrahman, head of the Britain-based Syrian Observatory for Human Rights, said anti-Assad fighters had killed six soldiers and wounded nine in the town of al-Herak, south of Deraa.
He also said seven people had been killed in Syria's north in and around Idlib province, three by a roadside bomb and the others by gunfire from Syrian security services.
In the suburbs of Damascus activists reported hundreds of arrests and said Syrian security forces had killed three people during raids in which they also set alight homes and cars.
Due to media restrictions, the activists' reports could not be independently verified.
Former Syrian ally Turkey said Assad was committing "war crimes" and condemned Syria for blocking aid to Baba Amro.
"The Syrian regime is committing a crime against humanity every day," Turkish Foreign Minister Ahmet Davutoglu said in a news conference with Italian Foreign Minister Giulio Terzi.
British Foreign Secretary William Hague said his government was again seeking to have the U.N. Security Council tackle the Syrian crisis.
"This means working with other countries such as Russia and China that have blocked previous initiatives," he told Sky News.
Russia and China twice vetoed council resolutions that would have condemned Damascus and demanded it halt the crackdown on anti-Assad demonstrators, accusing Western and Arab nations of pushing for Libya-style "regime change" in Syria.
The United States is drafting a legally binding council resolution that would call for aid workers to be allowed into besieged towns and an end to the violence, U.N. envoys said.
Western diplomats on Saturday received the bodies of American journalist Marie Colvin and French photographer Remi Ochlik, who were killed on Feb. 22 during shelling of Baba Amro.
A Reuters witness said the diplomats, believed to be the French ambassador to Syria and a representative from the Polish embassy, which is managing U.S. affairs in Syria, had taken the bodies from the Al-Assad University Hospital in Damascus. (Additional reporting by Oliver Holmes in Beirut, Stephanie Nebehay in Geneva, Michelle Nichols in New York, Avril Ormsby in London; Writing and additional by Mohammed Abbas; Editing by Mark Heinrich)