OKLAHOMA COUNTY -- Oklahoma County felt its fourth earthquake in seven days Sunday morning at about 2:40 a.m. The 3.4 magnitude quake was in the Jones-Spencer area in eastern Oklahoma County according to The United States Geologic Society.

People in Midwest City, Arcadia and as far as the Oklahoma City capitol area reported feeling the quake.

No damage was reported.

The Oklahoma Geological Survey says the number of earthquakes in Oklahoma County that have been strong enough to be felt is above average this year.

More than twice as many earthquakes were felt in the county this year than are normally felt in all of Oklahoma.

The biggest quake in Oklahoma this year measured 3.7 on the Richter scale and struck Aug. 28 in eastern Oklahoma County, near where three temblors have been recorded this month.

That quake is far in intensity from the last deadly earthquake in the United States, which killed two people in December 2003. The U.S. Geological Survey says that quake measured 6.6 and was centered near Paso Robles, Calif.

Scientists aren't sure what's causing the increase in earthquakes in Oklahoma.

The Associated Press contributed to this story.