Seventeen Sri Lankans working for an international aid agency were slain execution-style, and ambulances ferrying wounded civilians have been blown off the road.



The attacks in northern and eastern Sri Lanka took place during fierce fighting between Tamil Tigers and government troops dominated by the Sinhalese majority, and agencies say the conflict is becoming among the most dangerous for aid workers in recent years.



“Even in a war, there are certain (groups) that are not touched, such as the Red Cross symbol and NGOs,” said Jeevan Thiagarajah, executive director of the Consortium of Humanitarian Agencies, an umbrella for international and local aid agencies in Sri Lanka.



But in the recently resurgent Sri Lankan conflict, “both have been blown off the road, literally,” he said.



Thiagarajah cited two recent incidents.



On Aug. 21, a Tamil working for the Red Cross was shot and killed in the northern district of Vavuniya, an area controlled by the government.



Earlier in the month, two ambulances ferrying wounded were blown off the road during a fierce artillery battle for the eastern town of Muttur, killing one driver, according to the International Committee of the Red Cross.



Also in August, a road-side bomb exploded near an ambulance in a LTTE-held part of Vavuniya, killing five medical workers, including a doctor, the ICRC said.



“Who shot them off the road, I do not know,” said Thiagarajah, one of the few aid workers willing to speak publicly about the dangers facing humanitarian workers in Sri Lanka.



Others expressed similar concerns, but would only speak on condition of anonymity for fear of exacerbating risks to staff and their operations, which are already threatened by the near-daily air strikes, gun battles and artillery duels on the battlefields of northern and eastern Sri Lanka.



Then there was the discovery on Aug. 7 of 17 dead aid workers, all shot execution style. All but one were Tamils working for Action Against Hunger, an international aid group, in a part of Muttur controlled by the government.



It was the worst single attack on aid workers since the bombing of a U.N headquarters in Baghdad in 2003, and Action Against Hunger’s president, Denis Metzger, called the killings “deliberate.”



He did not say who he believed was behind the as-yet unsolved killings, but many here suspect the military was involved, largely because the slayings took place in a part of town firmly in the grip of security forces.



“There is a general climate that is hostile to non-governmental organizations working in the northeast and on the peace issue,” said Jehan Perera, an analyst at the independent National Peace Council.



Decades of discrimination against the largely Hindu Tamils, who account for about 3.2 million of Sri Lanka’s 19 million people, by the 14 million predominantly Buddhist Sinhalese led the Tigers to take up arms in 1983 to fight for a separate Tamil homeland in the north and east.



Several thousandpeople were killed before a 2002 cease-fire, which has all but disintegrated since late July as open warfare erupted along frontiers separating LTTE - and government-held territories in the north and east.



Fighting since July has displaced about 204,000 people, nearly all of whom are Tamil, and aid workers charge the government is intentionally limiting access to the newly homeless.



“Part of warfare is to batter people psychologically, and physically prevent them from getting help,” Thiagarajah said, noting that many of the displaced were running low on food and water.



The government counters that the restrictions are in place because it cannot guarantee aid workers’ safety in conflict zones.



“We don’t want to take a chance as the conflict is still going on. We are allowing them to go on a measured basis,” said Disaster Management Minister Mahinda Samarasinghe.



While most international agencies say relations with Tamil Tigers are good, the insurgents are no strangers to extra-judicial killings, and the military last week blamed them for killing an ethnic Sinhalese aid worker in the Tiger-held eastern town of Ampara.



The Tigers say the employee of the United Office Project Firm, a local group funded by New Zealand, was killed by a breakaway faction allegedly supported by the military.



Apart from obstructing aid reaching those forced from their homes by the latest fighting, the clashes are also hampering efforts to assist hundreds of thousands of people displaced by fighting before by the cease-fire and left homeless by the 2004 Indian Ocean tsunami.



Most of those people remain in squalid camps, many of which are in areas that are now too dangerous to work in, forcing several agencies - such as Oxfam, Care and Caritas - to suspend relief projects.



AP reporter Bharatha Mallawarachi contributed to this report.