Myanmar authorities have denied any civilian deaths but confirmed a clash took place after a rights group reported Several people including women and a child have been killed in an attack on Rohingya Muslims in western Myanmar.

The authorities on Friday confirmed that clashes had taken place, in which a police officer was presumed to have been killed, but said there had been no information about the killings of women and at least on child, as reported by Thailand-based advocacy group Arakan Project.

Details of the unrest on Friday were unclear, but Rohingya activists said at least two women and a child were stabbed to death in an attack on a village near the border with Bangladesh earlier this week, with possibly several dozen casualties.

The United States and Britain called on the government to investigate and to hold those responsible accountable.

"We have had no information about killings," Deputy Information Minister Ye Htut told reporters on the sidelines of a meeting of Southeast Asian foreign ministers in Myanmar's ancient city of Bagan.

His comments were echoed by other government officials.

Chris Lewa, director of the Thailand-based advocacy group Arakan Project, which has been documenting abuses against Rohingya for more than a decade, said details about the violence in Du Char Yar Tan village were still emerging, with many conflicting reports.

The death toll could be anywhere from 10 to 60, said Lewa, whose sources range from a village administrator to witnesses.

One described the slashed-up bodies of three acquaintances two women and a 14-year-old boy found in their homes.

Some of the victims also were hit by bullets, the group was told.

Grappling with violence

Medecins Sans Frontieres, or Doctors Without Borders, which runs a nearby clinic, said it was concerned that residents who are in hiding may not be getting the medical care they need.

"MSF confirms that on Wednesday it saw two wounded people suffering from injuries inflicted as a result of violence, one from a gunshot wound and the other exhibiting injuries consistent with a beating," said the group's Myanmar head, Peter-Paul de Groote.

Myanmar, a predominantly Buddhist nation of 60 million people, has been grappling with sectarian violence for nearly two years.

Myanmar's government considers the estimated 800,000 Rohingya in the country to be foreigners while many citizens see them as illegal immigrants from Bangladesh and view them with hostility.

More than 240 people have been killed and another 250,000 forced to flee their homes, most of them Muslims from the western state of Rakhine.