DENVER (AP) — Scientists say they have more evidence that an increase in earthquakes on the Colorado-New Mexico border since 2001 has been caused by wells that inject wastewater from oil and gas production back underground, similar to human-caused quakes in Oklahoma and other states.

A paper published last week by researchers at the University of Colorado concluded that the wastewater caused a big enough increase in underground pressure to make rock formations slip along fault lines.

"You find that the pressure changes at a given depth are enough to trigger earthquakes," said Jenny Nakai, the...