Oil prices seemed set for another volatile week, with both key benchmarks falling sharply on Monday on concerns that the world is running out of places to store excess supplies of crude due to a coronavirus-induced plunge in demand.

Crude prices have fallen in eight of the last nine weeks, with United States futures for May briefly plunging below $0 for the first time ever last week. Global demand has collapsed by about 30 percent due to the pandemic, leaving more oil than can be stored.

"Concerns surrounding rising global inventories, especially in the US with the coronavirus pandemic weighing on gasoline consumption are pressuring oil prices," Kim Kwang-rae, commodities analyst at Samsung Futures Inc, told the Bloomberg news agency. "While OPEC has started to curb output, demand is still not being supported and that's going to be a down factor for prices."

On Monday afternoon in Asia, US. crude was down $1.93, or 11.4 percent, to $15.01 per barrel, while Brent crude futures slipped 82 cents, or 3.82 percent to $20.62.

Meanwhile, Asian shares were mostly higher after the Bank of Japan (BOJ) announced more stimulus steps to help cushion the economic effect of the coronavirus.

MSCI's broadest index of Asia-Pacific shares outside Japan rose 1.8 percent, taking back a chunk of last week's 2.6 percent decline. Japan's Nikkei gained 2.6 percent, and Chinese blue chips 1 percent.

After a soft start, E-Mini futures for the US S&P 500 index climbed 1 percent, while EUROSTOXX 50 futures added 2.6 percent and FTSE futures 1.5 percent.

The BOJ matched market expectations by pledging to buy unlimited amounts of government bonds, removing its previous target of 80 trillion yen ($747bn) per year.

Japan's central bank sharply raised its purchases of corporate and commercial debt and eased rules for what types of debt would qualify for its bond-buying program.

Central banks have been buying bonds as a way to inject funds into financial markets and to lend to companies that are running short on cash - a process known as quantitative easing (QE) - as demand for goods and services dries up due to government-mandated lockdowns to prevent the spread of the virus. 

Indefinite support

The US Federal Reserve, also known as the Fed, and the European Central Bank will meet later in the week, with the latter likely to increase its bond purchases.

"For the Fed, no further developments on QE or interest rates are expected, but we expect it to underline that its policies will be in place indefinitely to support the economy," Australian bank ANZ wrote in a research note.

"We expect the ECB to raise the size of its emergency bond-buying package (PEPP) by about 500 billion euros [$541bn] to 1.250 trillion [$1.35 trillion] and to continue pressing for a sizeable fiscal stimulus."

On the data front, the US and European Union release gross domestic product (GDP) for the first quarter and the influential US ISM survey on manufacturing.

Earnings season will be in full swing with around 173 companies in the S&P 500 reporting this week, including Apple, Amazon, Facebook, Microsoft, Caterpillar , Ford, General Electric and Chevron.

Analysts expect a 15 percent decline in S&P 500 first-quarter earnings, with profits for the energy sector estimated to slump more than 60 percent, raising fears of debt defaults, layoffs and possible bankruptcies.

The dollar has been firmer in recent days thanks to its safe-haven status as the world's most liquid currency during times of stress, although moves have been relatively mild in recent weeks.

The dollar index touched a three-week high at 100.860 on Friday before easing back to 100.150 on Monday amid an improvement in risk appetite.

The euro edged up to $1.0843, having hit a one-month low of $1.0725 on Friday, while the dollar eased slightly on the yen to 107.24.

Gold held at $1,722 per ounce, after gaining 2.5 percent last week.