PITTSBURGH — Artwork valued in the thousands of dollars was stolen from several artists at Pittsburgh's Three Rivers Arts Festival.

The thefts occurred between Saturday night and Sunday morning. The artists arrived to find their works gone.

The festival has 24-hour security and it's not clear how some of the larger pieces were stolen without anyone noticing.

In a statement, the Pittsburgh Cultural Trust called the thefts “an unfortunate occurrence.” It has increased security in the market area.

CLEVELAND (AP) — Federal geologists say an earthquake of an estimated magnitude 4 has hit just northeast of Cleveland in Lake Erie, shaking up residents who flooded dispatch centers with calls.There were no immediate reports of damage from the earthquake of preliminary depth of 3.11 miles (5 kilometers). The U.S. Geological Survey is collecting responses from people who felt tremors. Magnitude 4 earthquakes can cause moderate damage.The earthquake hit at 10:50 a.m. EDT Monday and was about 2.5 miles (4 kilometers) from Eastlake, a city of nearly 20,000 people.The City of Mentor urged people to stop calling 911 unless they had an emergency because dispatchers were being “overwhelmed.”Andrew Nyblade, professor in Penn State’s College of Earth and Mineral Sciences, says northeastern Ohio has a history of seismic activity, including magnitude 4 earthquakes.