According to new official figures, about 400 people have died in Rakhine State since last Friday.
Among the dead were women and children who drowned while trying to cross a river to take refuge in neighboring Bangladesh.
The military intensified attacks on Rohingya Muslims last Friday after dozens of police and border outposts in Rakhine allegedly came under attack by a group that says it is defending the rights of the Rohingya.
The Muslim community has been under a military siege in Rakhine since October 2016. The government used a militant attack on border guards back then as the pretext to enforce the blockade. The Rohingya had already been subject to communal violence by extremist Buddhists for years.
UN sources also said on Friday that some 38,000 Rohingyas had managed to cross into neighboring Bangladesh.
The Rohingya Muslims fleeing to Bangladesh say the military has launched a campaign of arson and killings to force them out. They are forced to take perilous boat journeys across the Naf River, which straddles Myanmar Bangladesh.
On Friday, Bangladeshi border guards found the bodies of at least 15 Rohingya Muslims, including 11 children, floating in the river.
According to border guard commander Ariful Islam, the latest deaths brought the number of the Rohingya who have drowned this week to about 40.
Over 400,000 Rohingya refugees are already living in overcrowded, squalid camps and makeshift settlements in Bangladesh’s southern district of Cox’s Bazar.