Export prices for rice surged to a near four-year high in Vietnam this week due to strong demand, while slow buying interest put pressure on prices of Indian rice. The threat of floods also raised the prospect of Bangladesh stepping up purchases. Vietnam’s 5 percent broken rice prices rose to $455-$460 a tonne, their highest since August 2014, versus $445-$450 last week. Prices continue to rise on stronger demand and tight supplies. The Philippines is expected to purchase another 250,000 tonnes in an open tender on May 22, after accepting 250,000-tonne offers from Vietnam and Thailand last week. Vietnam exported 721,379 metric tonnes of rice in April, up 9.5 percent from March.