SINGAPORE (Reuters) – Oil markets on Friday remained weak as rising supply and concerns of an economic slowdown pressured prices, with US crude now down by around 20 percent since early October.

US West Texas Intermediate (WTI) crude oil futures were at $65.60 per barrel at 0509 GMT, down 4 cents, or 0.1 percent from their last settlement. WTI is set to fall for a fifth week, down 4.1 percent so far this week.

Front-month Brent crude oil futures were at $70.69 a barrel, 4 cents above their last close. Brent is set for a 2.9 percent drop for the week, its fifth straight week of declines.

Both Brent and WTI have declined by around 20 percent from the four-year highs they reached in early October.

“Oil prices continue to decline and are now officially in a bear market, having declined 20 percent from their (October) peak,” said William O’Loughlin, investment analyst at Australia’s Rivkin Securities.

Reuters technical commodity analyst Wang Tao said on Friday that “Brent oil may slide further into a range of $68.59-$69.69 per barrel.”

That would be the first time Brent has fallen below $70 since April.

Analysts said the main downward price pressure came from rising supply, despite the US sanctions against Iran that were imposed this week, as well as concerns over an economic slowdown.