As dawn broke in the area, about 50 miles north of where a deadly quake killed nearly 300 people in August
, rescuers were fearful of mudslides and wary about the risk of bringing heavy equipment up narrow roads linking the towns, villages and hamlets in this hilly region of the country.
The two temblors were followed by small aftershocks and one larger aftershock, measuring magnitude 4.3, which struck at 8:21 a.m. (2:21 a.m. ET) Thursday. There were no immediate reports of further damage resulting from that aftershock.
The second of the two quakes Wednesday -- with a magnitude 6.1 -- was 3.2 kilometers (2 miles) north of Visso and 58 kilometers (36 miles) from Perugia, the US Geological Survey reported.
A few hours earlier, a magnitude 5.5 quake struck the same region. The epicenter was about 9 kilometers away, south-southwest of Visso. That quake hit at 7 p.m. (1 p.m. ET) between Perugia and Macerata, according to ANSA.
Italy's Civil Protection Agency said one person injured in Visso was taken to a hospital in Camerino, nearly 20 miles away, while dozens of others required medical attention in health facilities in the area.
The agency said a fire department helicopter would take off as soon as weather conditions allowed to rescue five people stranded overnight because of a landslide in Acquasanta.
There was significant damage to some buildings in Visso and another town, Campi, where the tremors destroyed the historic church, San Salvatore -- the first severely damaged the 15th-century structure, and the second finished it off.
There were constant, small aftershocks throughout Thursday morning in Campi.
Residents, some with tears in their eyes, came to see what remained of San Salvatore, not only a part of the area's cultural heritage but also of significance as the scene of baptisms, weddings and funerals.
Civil Protection Agency officials assisted one elderly man carrying a basket of flowers he wanted to leave at the cemetery.
Earlier, streetlights, likely powered by generators, remained on in Campi, but houses were dark. In many small towns, in the pre-dawn hours, there was little light, further hampering rescue efforts.
Hundreds of people slept in their cars in Campi, with blankets covering the windows. Cars were parked everywhere -- streets, gas stations, parking lots. Some residents had their dogs with them.
Local media said one man had suffered a heart attack.
Residents expressed worry that another, bigger tremor might cause even more damage.
The US Geological Survey said both of Wednesday's earthquakes were shallow.
The main square and church in nearby Norcia, a couple of miles to the south, were badly damaged, but the church was still standing.
Reminders of August quake
Tommaso Della Longa, a spokesman for the Italian branch of the Red Cross, told CNN that many people left their homes after the first shock and went outside when the second earthquake hit about two hours later.
Visso is about 110 miles northeast of Rome and 50 miles north of Amatrice, the small town that lost about 270 residents when a magnitude 6.2 quake hit on August 24. Another 20 people were killed in nearby towns.
The impact from Wednesday's quakes was even felt in Rome.
Video recorded by CNN affiliate Rai television showed a road to Visso that was largely blocked by a massive boulder. Cars were having to drive carefully around it.
Stone buildings in the town also were heavily damaged.
Della Longa said buildings that fell in the Amatrice area have been unoccupied since the August quake. The area remains off-limits. People displaced by that quake have been forced to move once again.