Oil prices were down on Wednesday over a more-than-expected build-up in US crude inventories, which is intensifying investor concerns over demand recovery at a time when some countries have started to impose new restrictions to battle the coronavirus.

International benchmark Brent crude was trading at $40.86 per barrel at 0647 GMT for a 1.80% decrease after closing Tuesday at $41.61 a barrel.

American benchmark West Texas Intermediate (WTI) was at $38.69 a barrel at the same time for a 2.22% decrease after ending the previous session at $39.57 per barrel.

The estimated increase in US crude inventories and a surge in the coronavirus cases, especially in the US and Europe, were the main factors that spurred oil price declines while fueling weak demand concerns amid the oil supply glut.

Late Tuesday, the American Petroleum Institute (API) announced its estimate of a rise of 4.6 million barrels in US crude oil inventories relative to the market expectation of a 1.2 million-barrel rise.

If crude stocks increase in line with the API’s expectations, it signals that crude demand is falling in the US, the world's largest oil consumer, to push prices down.

The rapidly rising number of coronavirus cases is forcing many countries worldwide to announce fresh restrictions and lockdowns, as the number of cases has now reached over 43.9 million, according to the latest data from Johns Hopkins University.

In Chicago, indoor dining and bar services were banned and gatherings in one place were limited. Italy, France, Germany and Spain also announced tighter restrictions.

The long-awaited US coronavirus economic relief deal, however, is still at a loose end due to the divergence between the US President Donald Trump and Democrats although Trump signaled a possible deal after the presidential election on Nov. 3.