(BRUSSELS) - The European Union expressed regret Thursday at the failure to launch a probe into alleged war crimes committed by the Sri Lankan military during its offensive against Tamil Tiger rebels.

On Wednesday, the UN Human Rights Council adopted a resolution proposed by Sri Lanka and non-aligned states that welcomed Colombo's pledges to seek reconciliation and resettle "the bulk" of displaced people within six months.

But it turned down the tougher approach advocated by Western nations, including the need to investigate alleged violations at the final stages of the nearly three-decade-old conflict, as Sri Lanka rallied Asian support. 

"The EU regrets that it was not possible for the Human Rights Council to agree on an acceptable outcome of the special session addressing the serious human rights violations and the humanitarian crisis," a statement said. 

"We regret that the proposals presented by the EU to amend the Sri Lankan draft resolution could be neither discussed nor considered by the council" after a "closure of debate" rule was supported by a majority of members. 

"Such motions contradict the very spirit in which the Human Rights Council was conceived," the Czech presidency of the 27-nation bloc said. 

The Tamil Tiger rebels were accused of holding tens of thousands of Tamil civilians as human shields, but government troops were alleged to have indiscriminately shelled rebel-held areas packed with civilians. 

The EU said that the outcome of the rights council meeting in Geneva "does not, in our view, address the complexity and the seriousness of the situation on the ground." 

It said it would continue to work with the UN and its agencies to alleviate the suffering of civilians on the ground and to work for the achievement of durable stability."