(Washington) Commercial crude oil reserves rose sharply last week in the United States, according to figures released Thursday by the United States Energy Information Agency (EIA), notably due to an increase in imports.

In the week ended May 26, commercial inventories rose by 4.5 million barrels, while analysts saw them fall by 1.5 million, according to a consensus compiled by the Bloomberg agency.

This increase in inventories comes after an exceptional drop the week before, which had seen reserves melt by more than 12 million barrels.

The increase recorded last week is somewhat offset by the fact that the government has further drawn on the strategic petroleum reserves (SPR) which decreased by 2.5 million barrels to stand at 355.4 million.

Crude imports increased by 1.3 million barrels per day.

The utilization rate at US refineries also rose to 93.1% from 91.7% the week before.

Gasoline reserves fell slightly (-0.2 million) while analysts bet on a decline of 1.1 million. Those of distilled products increased by 1 million as expected.

U.S. crude production fell slightly to 12.2 million barrels per day, from 12.3 million the previous week.

Demand eased to 19.4 million barrels per day from 20.7 million the previous week.

On average over four weeks, an indicator closely followed by operators, deliveries of gasoline, kerosene and distilled products are higher than those of last year at the same time.

Despite the unexpected increase in crude inventories, prices were on the rise after the sharp declines of the past few days.

A barrel of Brent from the North Sea, for delivery in August, of which this is the first day of use as a benchmark contract, took 2.58% to 74.47 dollars.

Its US equivalent, a barrel of West Texas Intermediate (WTI) for July delivery, gained 3.25% to $70.30 around 11:40 a.m. EST.