Investors have also been spooked by US reports that North Korean leader Kim Jong-un had undergone cardiovascular surgery earlier this month and was in"grave danger".
However, focus is now on the June contract, which had trading volumes more than 30 times higher. That rose towards US$21 a barrel, from US$20.43 on Monday. "This isn't surprising, given flights are grounded and people are driving much less for work and leisure. If the economic reopening takes longer than expected, we could see pressure further out in the futures curve."
While the two have drawn a line under the dispute and agreed with other top producers to slash output by almost 10 million barrels a day, that is not enough to offset the lack of demand. Analysts warned the drop in stocks could be an indication that the recent surge may have been too much too quick and another sell-off is possible.CNN cited a US official saying Washington was"monitoring intelligence" that the leader was in"grave danger after a surgery". The report did not specify what the intelligence was.