HOUSTON (AP) — Oilfield services company Baker Hughes Inc. says the number of rigs exploring for oil and natural gas in the U.S. declined by two this week to 698.

The Houston firm said Thursday 536 rigs sought oil and 162 explored for natural gas amid depressed energy prices. A year ago, 1,811 rigs were active.

Among major oil- and gas-producing states, California and North Dakota each declined by two and Ohio, Oklahoma and West Virginia dropped one apiece.

Louisiana and Texas gained two rigs. Pennsylvania was up one.

Alaska, Arkansas, Colorado, Kansas, New Mexico, Utah and Wyoming were unchanged.

The U.S. rig count peaked at 4,530 in 1981 and bottomed at 488 in 1999.

The count, normally released on Fridays, was early this week because of the New Year's holiday.