The coalition also noted that the armed separatist Liberation Tigers of Tamil Eelam have long been implicated in serious human rights abuses, but says this provides no justification for alleged government abuses.
Colombo pulled out of a tattered 2002 truce with Tamil rebels in January in the belief that it could defeat the guerrillas.
Tens of thousands of people have died since the rebels launched a separatist campaign in 1972 for autonomy or independence for minority Tamils in the island's north and east in the majority Sinhalese country. Elections to the 47-member council, the UN's leading human rights body, will be held in New York on Wednesday, when candidate countries need an absolute majority -- or 97 votes from the UN's 192 nations -- to be elected.
Human Rights Watch (HRW) branded Sri Lanka one of the world's worst perpetrators of "disappearances" and abductions and described the situation in the island -- torn by a decades-old ethnic war -- as a "national crisis."