Australia stayed silent on alleged human rights abuses in Sri Lanka in exchange for cooperation in cracking down on people-smuggling, Colombo's new Prime Minister Ranil Wickremesinghe said Monday.

Wickremesinghe said former president Mahinda Rajapakse had agreed to help stop boats carrying asylum-seekers leaving for Australia if Canberra kept quiet about alleged abuses committed by the previous regime. 

Asylum-seekers in a detention center in Papua New Guinea said Sunday that Canberra was holding them "hostage" in an effort to deter others from paying people-smugglers to bring them to Australia.

After days of hunger strike protests on PNG's Manus Island, refugee advocates said asylum-seekers were continuing to protest against their 18 months of detention in the offshore location.

Australian Immigration Minister Peter Dutton said Friday he was worried about the "volatile situation" at a Papua New Guinea asylum-seeker camp after reports that detainees were swallowing razor blades and washing powder.

Australia sends asylum-seekers who try to enter the country by boat to offshore detention centers on Papua New Guinea and Nauru in the Pacific with no prospect of being settled on the mainland, even if they are genuine refugees.

Some 15 asylum seekers hoping to make it to Australia and detained in Papua New Guinea have sewn their lips together and 400 are on hunger strike, a report said Thursday.

A spokesman for Australian Immigration Minister Peter Dutton did not comment on the scale of the protest, while conceding that some asylum seekers at a detention center had harmed themselves. He insisted that the protest was "peaceful."

The Australian government failed in its duty to protect asylum-seekers at a camp in Papua New Guinea where a February riot left one dead and 69 injured, said a damning parliamentary report released Thursday.

Iranian Reza Barati was killed in the riot at the Manus Island detention center in February as tensions flared among inmates about their fate under Australia's hardline asylum-seeker policies.

A 6.8-magnitude quake struck off the coast of Papua New Guinea Sunday, U.S. seismologists said, but no destructive tsunami was expected.

The quake hit at a depth of 10 kilometers (6.2 miles) about 116 kilometers from the nearest city of Panguna on Bougainville Island, at 11.22am local time (0122 GMT), the United States Geological Survey said.

A 6.4-magnitude quake struck Friday off the coast of Papua New Guinea, the United States Geological Survey said, but no destructive Pacific-wide tsunami was expected.

The quake, which was initially reported at 6.9 magnitude before being revised lower, hit at a depth of 65 kilometers (40 miles) in the New Britain region.

Ukrainian troops and pro-Russian forces were engaged in fresh clashes in the eastern city of Donetsk on Friday as they traded blame over the death of a foreign aid worker four weeks into their shaky truce.

Australia has ordered an inquiry into claims of sexual misconduct by staff at a refugee camp in Nauru, including whether the reports were fabricated by aid workers, Immigration Minister Scott Morrison said Friday.

Phnom Penh and Canberra signed an agreement Friday for the resettlement of Australia-bound refugees in Cambodia, a deal the U.N. criticized as a "worrying departure from international norms".

Under its hardline immigration policy Australia already sends asylum-seekers arriving by boat to camps on Manus Island in Papua New Guinea and the remote Pacific state of Nauru for processing and resettlement.