DHAKA, May 13 (Reuters) - A powerful storm packing winds of up to 175 kph (109 miles) barrelled towards the coasts of eastern Bangladesh and Myanmar on Saturday, threatening around a million Rohingya refugees and others living in low-lying areas.

After brewing in the Bay of Bengal for days, Cyclone Mocha is likely to intensify further and make landfall between Cox's Bazar in Bangladesh and Myanmar on Sunday, Bangladesh Meteorological Department said in a bulletin.

Cox's Bazar, a southeastern border district, is where more than a million Rohingya refugees live, most having fled a military-led crackdown in Myanmar in 2017.

Mocha - categorised as a very severe cyclonic storm - is expected to cut a path through Myanmar's Rakhine and northwestern region, where six million people need humanitarian assistance and 1.2 million are displaced, the U.N. humanitarian office said.

Since a junta seized power two years ago, Myanmar has been plunged into chaos and a resistance movement is fighting the military on multiple fronts after a bloody crackdown on protests.

A spokesperson for the Myanmar junta did not respond to a phone call.

"We are focusing on saving lives," said Mohammad Shamsud Douza, a Bangladesh government official responsible for refugees. "People who are at risk of landslides will be evacuated."

Thousands of trained community workers and volunteers had already been deployed, alongside medical and rescue personnel who are on stand-by, he said.

In Myanmar, the World Food Programme said it was preparing food and relief supplies that could help more than 400,000 people in Rakhine and surrounding areas for a month.

Some people in Rakhine's capital Sittwe were either leaving their homes to seek shelter on higher ground or moving further inland, a resident said.

"Everyone is trying to leave town since yesterday afternoon," the 20-year-old said, asking not to be named, "Not many people remain in my street, just my family."