* UN investigators blame all sides for human rights crimes in Syria
* Say more and more civilians trying to arm themselves
* Foreign fighters arriving in Syria from around the world
By Justyna Pawlak and Stephanie Nebehay
BRUSSELS/GENEVA, Dec 20 Fighters from around the world have filtered into Syria to join a civil war that has split along sectarian lines, increasingly pitting the ruling Alawite community against the majority Sunni Muslims, U.N. human rights investigators said on Thursday.
The deepened sectarian divisions in Syria may diminish prospects for any post-conflict reconciliation even if President Bashar al-Assad is toppled. And the influx of foreign fighters raises the risk of the war spilling into neighbouring countries, riven by the same sectarian fault lines that cut through Syria.
"As battles between government forces and anti-government armed groups approach the end of their second year, the conflict has become overtly sectarian in nature," the investigators led by Brazilian expert Paulo Pinheiro said in an updated report.
As a result, they said, more civilians were seeking to arm themselves in the conflict, which began 21 months ago with street demonstrations demanding democratic reform and evolved into an armed insurgency bent on toppling Assad.
"What we found in the last few months is that the minorities that tried to stay away from the conflict have begun arming themselves to protect themselves," Karen Abuzayd, a member of the group, told a news conference in Brussels.
Syrian government forces had increasingly resorted to aerial bombardments, including shelling of hospitals, and evidence suggests that such attacks are "disproportionate", the report said. The conduct of hostilities by both sides is "increasingly in breach of international law", it added.
"Feeling threatened and under attack, ethnic and religious minority groups have increasingly aligned themselves with parties to the conflict, deepening sectarian divides."
FIGHTERS FROM 29 COUNTRIES
Most of the "foreign fighters" slipping into Syria to join rebel groups, or fight independently alongside them, are Sunnis from other countries in the Middle East and North Africa, the U.N. investigators found, reporting on their findings after their latest interviews conducted in the region.
"They come from all over, Europe and America, and especially the neighbouring countries," said Abuzayd, adding that names from 29 states had been recorded so far.
The report covers the period between Sept. 28 and Dec. 16, and will be part of a final document to be prepared in March.
It said the Lebanese Shi'ite Hezbollah had confirmed that group members were in Syria fighting on behalf of Assad.
Hezbollah has previously denied sending members to fight alongside Syrian government forces.
But Hezbollah held a series of funerals two months ago for Fighters killed "performing their jihadist duties" and leader Sayyed Hassan Nasrallah suggested they had been fighting in areas along the poorly defined Lebanon-Syria border.
The U.N. report also cited reports of Iraqi Shi'ites coming to fight and said Iran, a close ally of Assad, confirmed in September that its Revolutionary Guards were in Syria providing assistance. Tehran has denied military involvement in Syria.
Investigators also said human rights violations were being committed on all sides of the conflict and members of government and anti-government groups alike would be listed for possible referral to the International Criminal Court.
"As the conflict drags on, the parties have become ever more violent and unpredictable, which has led to their conduct increasingly being in breach of international law," the report said.
All sides, investigators added, were failing to "distinguish targets" and using civilian property for military purposes.