The fourth earthquake in 16 days hit East Texas early Saturday.

No injuries or significant damage were reported from the preliminary magnitude 2.5 temblor that hit about 1:30 a.m., said Larry Burns, emergency management coordinator in Timpson.

The quake was centered about seven miles southeast of town, near FM 1645 and Texas 87, according to information from the U.S. Geological Survey.

"One of the guys I work with, he told me it shook but it wasn't like any of the others we've had," said Burns, who was not in town when the latest quake occurred. "We're up to four of them so far."

There perhaps have been more than that, according to accounts collected by the Timpson and Teneha News, Mayor Debra Smith said Saturday.

"I think they've determined we are up to seven in the last 12 months," the mayor said, dating the first reports to July. "But some of them were smaller than the (Geological Survey) keeps up."

Smith reported the most recent shakeup was less dramatic than a May 17 quake that recently was upgraded to magnitude 4.8, woke residents and was blamed for one injury in the northern Shelby County town of 1,166.

"I think some people felt it," she said, adding she slept through the latest quake. "We don't know if it was an aftershock or how they classify those."

The first quake, on May 10, measured magnitude 3.7. The May 17 earthquake was followed three days later by a 2.7 tremor that struck at 1:28 p.m. one week ago today about a mile south of Timpson.

The May 17 quake, which was felt in Longview and Shreveport, was centered three miles east of town, while the May 10 shakeup emanated from a site four miles to Timpson's northeast.

Since the quakes began, Smith said, teams from the U.S. Geological Survey and Stephen F. Austin State University have placed seismic monitors in two or three locations to continuously record underground activity.

Several residents expressed suspicions that mineral extraction could be a factor in the unusual seismic activity.

"It's kind of unnerving," Smith said. "Everybody I talked to said it's too early to determine if there is any connection to the oil and gas industry and anything significant causing it."