OPEC's oil production spiked to a 3-year high in July

The 12-member oil cartel OPEC continues to pump oil at an unrelenting pace.

On Tuesday, the group's monthly oil market report showed that it pumped the most oil in three years last month, citing secondary sources. Member countries pumped an average of 31.5 million barrels per day in July.

The increase was boosted by output from Iraq, Angola, Saudi Arabia, and Iran, the group said.

Crude oil prices have come under pressure in recent months on concern that the market continues to be oversupplied, and that there isn't a balance of demand.

OPEC has maintained and exceeded its production targets to guard its share of the market, amid competition from other global players including US shale oil producers.

On Tuesday morning, West Texas Intermediate crude oil futures were down about 1.5%, near $44.29 per barrel in New York. Brent crude, the international benchmark, fell about 1.3% to about $50.34. On Monday, Brent saw its biggest intraday jump in a month.

Here's a chart showing OPEC production compared to the rest of the world's output.