By Stephanie Nebehay and Tom Miles
GENEVA (Reuters) - The death toll in Syria reached at least 93,000 at the end of April, but the true number of victims from the violence now in its third year may be much higher, the United Nations human rights office said on Thursday.
Navi Pillay, U.N. Commissioner for Human Rights, voiced fears that the bloodshed in recent battles for the Syrian border town of Qusair would be repeated in the northern city of Aleppo.
"All the reports I'm receiving are of augmentation of resources and forces (for an Aleppo offensive) on the part of the government," Pillay told Reuters Television.
The military balance has shifted in President Bashar al-Assad's favour in the last two months, with Lebanon's Shi'ite Hezbollah fighting openly alongside the Syrian military, helping it to recapture Qusair from rebels on June 5. Rebel forces have held parts of Aleppo, Syria's biggest city, since July.
The new U.N. figure of 93,000 people killed in the Syrian conflict, which began with peaceful protests against Assad in March 2011 and turned into an armed rebellion a few months later, replaces a U.N. estimate of 80,000 issued in mid-May.
The U.N. report said almost 38,000 reported killings had been excluded because records - which require the victim's full name and date and location of death - were incomplete.
"The true number of those killed is potentially much higher," Pillay said.
The death toll has averaged more than 5,000 a month since July, and Pillay said this reflected the "drastically deteriorating pattern of the conflict over the past year".
The Damascus region, Homs and Aleppo have been hardest hit.
The U.N. figures, based on data from the Syrian government and seven human rights monitoring groups, include civilians and combatants, but give no breakdown. They show that at least 6,561 children were among the dead.
"There are also well-documented cases of individual children being tortured and executed, and entire families, including babies, being massacred - which, along with this devastatingly high death toll, is a terrible reminder of just how vicious this conflict has become," Pillay said.
One of the monitoring groups, the British-based, pro-opposition Syrian Observatory for Human Rights, said on Thursday it had now confirmed at least 98,000 deaths in the conflict, but that the total figure could exceed 130,000.
It said the confirmed toll included 25,040 Syrian soldiers and security personnel, and 17,107 pro-Assad militiamen.
Other killings are likely to have occurred without being documented, said the U.N. study, carried out by the Human Rights Data Analysis Group, a U.S.-based non-profit organization.
(Here is a link to the full report: http://www.ohchr.org/Documents/Countries/SY/HRDAG-Updated-SY-report.pdf )
(Additional reporting by Vincent Fribault in Geneva and Oliver Holmes in Beirut; Editing by Alistair Lyon)