NEW YORK (AP) — The price of oil is climbing on reports that U.S. factories have cranked into a higher gear.

Benchmark U.S. crude increased Monday by $1.07 to $104.09 per barrel in New York while Brent crude rose by 68 cents to $123.56 per barrel in London.

Manufacturers are big users of diesel fuel, so increased factory activity usually means increased demand for diesel. The Institute for Supply Management, a trade group of purchasing managers, reported that U.S. manufacturing grew in March at a faster pace than the previous month.

Retail gasoline prices were flat over the weekend, with the national average holding at $3.925 per gallon. Natural gas futures fell to a 10-year low, losing 1.9 cents to $2.107 per 1,000 cubic feet.