Prices of Thai rice hit their highest in nearly four years while those of the Vietnamese grain rose to their strongest in more than two years on strong demand from key importing countries. Thailand’s benchmark 5-percent broken rice RI-THBKN5-P1 was quoted at $440-$457 a tonne, free-on-board (FOB) Bangkok, up from $430 last week. Exporters are now buying the grain at much higher prices than when deals were struck, while some have shied away from fresh deals. Thailand has exported 5.09 million tonnes of rice so far, this year, up 15.7 percent from the same period last year.