ROME -- Four strong earthquakes on Wednesday shook the same region of central Italy that suffered deadly temblors last year, sending quake-rattled residents into panic and further isolating towns that have been buried under more than a meter (3 feet) of snow for days.

Premier Paolo Gentiloni said it appeared no one was killed, but that it was a "difficult day" for Italy.

The first tremor, with a preliminary magnitude of 5.3, hit Montereale at about 10:25 a.m. (0925 GMT), according to the U.S. Geological Survey. A second quake with a magnitude of 5.7 hit the same area about 50 minutes later, and 10 minutes later a third was measured at magnitude 5.3. Several hours later another 5.1-magnitude quake shook the same area.

Throughout the day, seismologists registered more than 100 aftershocks.

Several towns and hamlets in the quake zone had already sounded the alarm in recent days that they were without electricity and were isolated from highways due to the unusually heavy snowfall that has blanketed much of central Italy.

The quakes only made matters worse, knocking out some cellphone service, hampering emergency response and sending quake-weary residents into panic. The Defence Ministry promised to send in army units to help.

"The situation is really getting extreme," said the mayor of Canzano, Franco Campitelli. "It's snowing hard. We're without electricity. We hope the army gets here soon with snow plows or we risk being completely isolated," he told Sky TG24.

The quakes, which had their epicenters in the L'Aquila region, were felt as far away as Rome, 150 kilometres (100 miles) to the southwest.

In the Italian capital, the subway was closed for hours as a precaution, parents were asked to pick up their children from some schools, and offices, banks and shops were evacuated temporarily.

But elsewhere in Rome at the Vatican, Pope Francis' Wednesday general audience went off without a hitch.

In the Umbrian pilgrimage town of Assisi, friars closed the Santa Maria degli Angeli basilica as a precaution. The basilica hosts the famed Porziuncola chapel, birthplace of the Franciscan order of the pope's namesake, St. Francis of Assisi.

Three quakes in mountainous central Italy last year killed nearly 300 people in and around the medieval town of Amatrice and caused significant damage to older buildings. The tower of one of Amatrice's churches toppled in Wednesday's quakes.

L'Aquila itself suffered a devastating 6.3-magnitude earthquake in 2009 that killed more than 300 people.

Mayor Maurizio Pelosi of Capitagno, near the epicenter of Wednesday's quakes, said even before the earth shook many roads into and out of the town were blocked due to the snow.

A hotel worker in town, Giuseppe Di Felice, told state-run RAI radio people couldn't get out of their homes. "It's apocalyptic," he said.

AP writer Frank Jordans in Berlin contributed