GENEVA - Syrian forces have shot dead unarmed women and children, shelled residential areas and tortured wounded protesters in hospital under orders from the "highest level" of army and government officials, the United Nations said on Thursday.Independent UN investigators called for perpetrators of such crimes against humanity to face prosecution and said they had drawn up a confidential list of names of commanding officers and officials alleged to be responsible.Armored forces loyal to Assad moved into the rebel district of Baba Amro in Homs on Thursday, opposition sources said.Syria is "on the brink" of civil war and deep divisions among world powers complicate the prospects for ending nearly a year of violence sparked by protests against the regime, the three-member UN panel said in their latest 72-page report."The continuation of the crisis carries the risk of radicalizing the population, deepening inter-communal tensions and eroding the fabric of society," it warned.Satellite images corroborate testimonyThe UN team was not allowed into Syria but said it had interviewed 369 victims and witnesses. They included people still in Syria whom it contacted by telephone and those who have fled to neighboring countries which it declined to identify."Satellite imagery of areas where military and security forces were deployed and related reported violations occurred, corroborated a number of witness accounts," it said.Thousands of people, mainly civilians but also soldiers and defectors, have been killed during the nearly year-long crackdown, it said."Army snipers and Shabbiha gunmen posted at strategic points terrorized the population, targeting and killing small children, women and other unarmed civilians. Fragmentation mortar bombs were also fired into densely populated neighborhoods."Some 6,399 civilians and 1,680 army defectors were killed in the violence through Feb. 15, according to figures provided by the Violations Documentation Center, a network of activists in Syria and abroad quoted in the UN report.The level of fighting has increased since November, especially in Homs, Hama and Idlib provinces, with many areas besieged by state forces, according to the report."The commission received credible and consistent evidence identifying high- and mid-ranking members of the armed forces who ordered their subordinates to shoot at unarmed protesters, kill soldiers who refused to obey such orders, arrest persons without cause, mistreat detained persons and attack civilian neighborhoods with indiscriminate tanks and machine-gun fire," investigators said in a report to the UN Human Rights Council.The commission of inquiry, headed by Brazilian Paulo Pinheiro, found that rebel forces led by the Free Syrian Army had also committed abuses including killings and abductions, "although not comparable in scale".Syrian authorities could not be immediately reached for comment on the commission's findings.Syrian President Bashar Assad's forces bombarded opposition Sunni Muslim districts in the city of Homs for the 20th day on Thursday, activists said, despite international outrage over the reported killing of more than 80 people on Wednesday.