The number of oil and natural gas drilling permits issued by Texas regulators in April was lower year-on-year by 20 percent, state data show.

The Railroad Commission of Texas said it issued 683 original drilling permits in April, compared with 848 from the same month one year ago. Most of the permits were for oil-related activities.

Weekly data published Friday by oil field services company Baker Hughes show 188 rigs actively exploring for or producing oil and natural gas in Texas, a gain of 1.6 percent from the previous week, but 50 percent lower than the same week in 2015.

In February, the last full month for which state data are available, Texas produced 79.6 million barrels of oil, a figure that was lower year-on-year by around 17 percent.

Texas is the No. 1 oil producer in the United States and its rig count represents roughly 45 percent of all activity in the country. A low price for crude oil has taken a toll on the state economy, as many energy companies with headquarters in Houston lay off staff or close their offices altogether.

Texas Railroad Commissioner Christi Craddick said in a March editorial in the Midland (Texas) Reporter-Telegram it was only a matter of time before the sector recovered.

"While the overall decline in oil prices has led to falling revenues for the energy sector and job loss in the oil fields, it seems we are touching the bottom of this market cycle on our way to a bigger upside," she said.

The price for crude oil has increased 12 percent since the March editorial was published.

In terms of discoveries, state data show four new oil finds recorded in April, against three recorded in April 2012. Nevertheless, March data provided by Platts Analytics show production from the Eagle Ford shale basin in Texas, one of the more lucrative reserve areas, declined about 3 percent in March for the eighth straight month of loss.