By Stephanie Nebehay
GENEVA, March 10 (Reuters) - Three northeastern provinces of Syria face an "alarming" food crisis, although access to relieve the impact of civil war has improved somewhat elsewhere, a U.N. aid agency said on Monday.
Western powers and U.N. human rights investigators have accused the Syrian government of a policy of "starvation until submission" to punish tens of thousands of civilians in rebel-held areas. Opposition forces are besieging two Shi'ite Muslim villages with a total of 45,000 people in Aleppo province.
Days before the Syrian conflict enters its fourth year, the World Food Programme (WFP) said the hardest areas to reach were the northeastern provinces of Raqqa, Deir al-Zor and Hassaka.
"We don't have total absolute numbers on deaths due to starvation. There are no massive indications of that. But there are certainly widespread (and) what I would call alarming nutritional indicators," Amir Abdulla, the U.N. agency's deputy executive director, told a news briefing in Geneva.
"The high levels of acute malnutrition are in the besieged areas or areas that we have been unable to access," he said.
Fighting and restrictions still hinder aid deliveries in parts of 12 of Syria's 14 provinces, WFP said in a statement.
"There has been a certain degree of increased access. But I stress that sporadic or one-off convoys, whilst providing temporary relief, don't provide the sort of sustained access and assistance that the people in those areas need," Abdulla said.
Access has eased since a unanimous U.N. Security Council resolution on Feb. 22 told all sides to boost aid and threatened "further steps" in case of non-compliance, Abdulla said.
But he said much remained to do, citing Homs and Aleppo as two areas where the United Nations was pushing for more access.
In February, WFP food rations failed to reach half a million of the 4.2 million Syrians who need them.
But the agency said it had delivered rations for the first time in months to 71,500 people living in four limited-access areas in Idlib, Deraa, Deir-al Zor and the Damascus countryside.
Locally-negotiated truces enabled convoys to reach parts of Deraa and the Damascus countryside, the statement said.
In recent days, the WFP delivered food to 20,000 people in Houla in rural Homs for the first time since May. Trucks with rations for 20,000 people arrived in Raqqa province for the first time in six months. Food aid also reached 17,500 displaced people living in camps in Harem, north of Idlib.
But Raqqa, the only province completely under rebel control and where nearly 285,000 people need aid, remained largely inaccessible for the fourth straight month, WFP said.
Humanitarian conditions in Deir-al-Zor are "rapidly worsening" amid food shortages and soaring market prices that put more than 550,000 people "at risk of food insecurity".
Deliveries in Deir al-Zor were a fraction of those planned due to fighting and the presence of armed groups on access roads.
Abdulla said shifting front lines and the need to negotiate with diverse combatants complicated WFP's aid efforts.
"There are certain groups who basically have stated that they do not want international humanitarian organisations to come into their areas. And in some of those areas, humanitarian workers, basically their lives are under threat, and we're not able to operate there," he said.
The WFP programme, which also feeds some 2 million Syrian refugees in neighbouring countries, costs $40 million a week. (Reporting by Stephanie Nebehay; Editing by Alistair Lyon)