NOSARA, Costa Rica — A powerful, magnitude-7.6 earthquake shook Costa Rica and a wide swath of Central America on Wednesday. There were no immediate accounts of injuries, but communications were down near the epicenter.

The USGS said the 8:42 a.m. quake struck about 38 miles (60 kilometers) from the town of Liberia. It was centered about 25 miles (41 kilometers) below the surface. The magnitude initially was estimated at 7.9.

In the town of Hojancha near the epicenter, city official Kenia Campos said the quake knocked down some houses and landslides blocked two roads.

“So far, we don’t have victims,” she said. “People were really scared … We have had moderate quakes but an earthquake (this strong) hadn’t happened in more than 50 years.”

There were no initial reports of damage or deaths in the capital of San Jose, said Douglas Salgado, a geographer with Costa Rica’s National Commission of Risk Prevention and Emergency Attention.

Salgado said, however, officials were having problem accessing the earthquake zone or reaching people there and were flying over the area to assess damage to highways and other structures.

The earthquake didn’t knock out phones or electricity in the capital 88 miles (141 kilometers) from the epicenter, Salgado said by telephone, but communications were down near the epicenter.

“There’s chaos in San Jose because it was a strong earthquake of long duration,” Salgado said. “It was pretty strong and caused collective chaos.”

At the Hotel Punta Islita in the Guanacaste area, “everybody is crying a lot and the telephone lines are saturated,” said worker Diana Salas, speaking by telephone, but she said was no damage there

In the coastal town of Nosara in northwest Costa Rica, trees shook violently and light posts swayed. Teachers chased primary school students outside.

A tsunami warning was in effect for Costa Rica, Panama and Nicaragua, the Pacific Tsunami Warning Center said in a bulletin. It said it was unknown if a tsunami was generated, but the warning was based on the size of the earthquake.