LONDON (Reuters) - Sri Lanka must investigate allegations of atrocities committed during its civil war after more video footage was aired claiming to show "horrific scenes" of bound prisoners being executed, Britain said on Wednesday.
Foreign Office Minister Alistair Burt said a failure to probe the claims of human rights abuses at the end of the 25-year war with guerrillas of the Liberation Tigers of Tamil Eelam (LTTE) could lead to international action against Colombo.
Burt's comments came after Channel 4 broadcast a documentary "Sri Lanka's Killing Fields" late on Tuesday which appeared to show the summary execution of Tamil prisoners by government soldiers.
The new video evidence, allegedly captured on mobile phones, showed three people including a woman, who appeared to be bound and blindfolded, being shot.
"I was shocked by the horrific scenes I saw in the documentary," Burt said in a statement.
"The recent U.N. Panel of Experts' report, this documentary and previously authenticated Channel 4 footage, constitutes convincing evidence of violations of international humanitarian and human rights law.
"The whole of the international community will expect the Sri Lankans to give a serious and full response to this evidence."
Last month, other footage obtained by Channel 4 which apparently showed soldiers executing naked men and women, led to condemnation from Christof Heyns, the U.N.'s special rapporteur on extrajudicial, summary or arbitrary executions.
Heyns said the video was, on the face of it, convincing evidence of "serious international crimes".
Sri Lankan authorities rejected the footage as falsified and accused the United Nations of bias and jumping to hasty conclusions.
Colombo has also accused the international community of trying to pre-empt its own Lessons Learned and Reconciliation Commission.
Burt said Britain had been calling for a thorough, independent probe into claims of war crimes since the conflict ended in 2009.
He said the government now expected to see progress by the end of the year, a message he had reiterated to Sri Lanka's foreign minister on Tuesday.
"If the Sri Lankan government does not respond we will support the international community in revisiting all options available to press the Sri Lankan Government to fulfill its obligations," he warned.