Import prices increased at their fastest pace in 18 months in May on a continued rise in crude oil prices. 

According to preliminary data from the Bank of Korea(BOK) on Tuesday, the import price index came to 87-point-09 last month, up two-point-seven percent from a month earlier. 

The monthly growth is the largest since November 2016, when it marked four-point-two percent. 

The index, which has been growing for five straight months since January, is also the highest since November 2014 when it posted 91-point-23.   

The BOK attributed the increase to a sharp rise in prices of Dubai crude, which soared nine percent on-month to an average of 74-point-41 U.S. dollars in May. 

The export price index rose point-nine percent on-month to 84-point-63 in May.