Syria is using snipers and helicopter gunships in its efforts to quash three months of protests, a U.N. report says.

U.N. High Commissioner for Human Rights Navi Pillay in a report pubished Wednesday said the regime of Bashar al-Assad had killed more than 1,100 and detained another 10,000  in "alleged breaches of the most fundamental rights."

U.N. investigators collected evidence for the report using evidence from rights groups and people who had fled Syria, after they were denied entry to the country despite repeatedly appealing to Damascus to let in a humanitarian team.

The U.N. has come under fire for its perceived silence on alleged human rights abuses by the Syrian regime.

According to the BBC:

Assad is facing the gravest threat to his family's 40-year ruling dynasty, as unrest that first erupted in the south of the country has now engulfed the north — near the border with Turkey — and is threatening to spread eastwards towards its border with Iraq.

Pillay said her office had a "considerable amount" of information that indicated Syrian authorities were in routine violation of conventional human rights laws, UPI reports.

The report cites "the excessive use of force in quelling demonstrators, arbitrary detentions, summary executions, torture," with information to suggest that the torture of detainees had resulted in deaths in custody.