(Adds U.S. statement, details)
By Ranga Sirilal
COLOMBO, July 3 (Reuters) - Sri Lanka should end arbitrary detentions of displaced civilians and allow humanitarian agencies to access those people affected by protracted civil war, Human Rights Watch (HRW) said on Thursday.
Separately, a visiting U.S. official expressed concerns over human rights issues and media conditions in the country.
Fighting between Sri Lanka's military and Tamil Tiger rebels has entered a new, intensified phase since the government formally pulled out of a 6-year-old Norway-brokered ceasefire pact in January.
The fighting is now concentrated in the north amid near daily land, sea and air attacks as the government pursues a strategy to gradually retake the Tigers' northern stronghold and win the civil war, after earlier capturing rebel-held areas in the east.
International rights group HRW urged the government to end arbitrary detention at a newly established camp in northern Sri Lanka of more than 400 civilians displaced by recent fighting.
"The Sri Lankan government shouldn't treat civilians as criminals just because they're fleeing a conflict area," said Brad Adams, Asia director at HRW, in an emailed statement.
Meanwhile, U.S. Deputy Assistant Secretary of State for South and Central Asian Affairs Evan Feigenbaum, in the country as part of regular consultations with the government, said in a statement: "We continue to have strong concerns about human rights and pressures on the media."
Sri Lankan journalists have recently suffered increasing assaults from unidentified gangs. One journalist was hacked to death in May in the island nation's northern district of Jaffna.
Media and rights groups have said government statements accusing critical journalists of treachery in the civil war against the rebels could trigger violence against the media.
Sri Lanka has intermittently censored media reports of the civil war since it began, and has restricted access to Tamil Tiger-held areas.
The civil war resumed in earnest in 2006 as the ceasefire effectively collapsed, even though the government's formal pullout only came this year.
Thousands of civilians have fled their homes to escape the fighting, while rights groups have reported hundreds of abductions, disappearances and killings blamed on one side or the other.
The conflict between the government and the Liberation Tigers of Tamil Eelan (LTTE), fighting to create an independent state for ethnic minority Tamils in the north and east, has waxed and waned since 1983, killing nearly 70,000 people.
The New York-based HRW also said the Sri Lankan government had severely restricted humanitarian access to rebel-held areas, leaving an estimated 107,000 displaced persons with inadequate relief, including in water and sanitation.
"Ensuring that humanitarian organisations have access to those affected by the fighting should be a priority concern, not an afterthought," Adams said, adding many displaced people who are in LTTE areas are in need of humanitarian assistance.
The group also said the rebels continued to prevent civilians from leaving areas under their control, thereby impeding people's ability to seek safety in other parts of the country.
"Both the LTTE and the government have a poor record of providing aid to populations at risk," Adams said.
Analysts say the military has the upper hand in the latest phase of the long-running war given superior air power, strength of numbers and the swathes of terrain captured in the island's east. But they still see no clear winner on the horizon.
The Tigers are regularly hitting back with roadside bombs and suicide attacks increasingly targeting civilians, experts and the military say, which have deterred some tourists and have worried some investors in the $27 billion economy. (Editing by Jerry Norton)