In the largest of a series of temblors to shake the region this weekend, a 5.6-magnitude earthquake hit Lincoln County, Okla., near midnight on Saturday, causing at least three sections of a major highway to buckle, according to an emergency-services spokesperson. No major injuries were reported, although there were reports of several cracked buildings. At about 3:30 a.m. Sunday, a 4.0-magnitude quake hit the state’s central region. Roughly 24 hours earlier, a 4.7 quake hit in the same area. Some 30 aftershocks were felt as far away as Texas and Wisconsin. The biggest earthquake previously reported in Oklahoma was a 5.5 in 1952, according to the Oklahoma Geological Survey.