Peru's Geophysics Institute said the quake struck at 8:55 p.m. Sunday (0155GMT Monday) and was centered about 56 miles northeast of the jungle city Moyobamba, 415 miles north of the capital, Lima.
"Several houses have fallen down and there are several people dead," Carlos Mori, a resident of the jungle town of Lamas, near Moyobamba, told Radioprogramas. "All of the residents of Lamas are in the streets. Most of the people are helping."
Mori said about 20 houses had collapsed and that four people were dead.
But Napoleon Salazar, a regional official in the Department of San Martin, told The Associated Press that "there are nine injured in the hospital and one fatality" in Lamas.
A policeman in Lamas confirmed that only one person was known to have died and told the AP that eight houses were completely destroyed and about 30 others damaged.
A police officer in the jungle town of Tarapota, 12 miles southeast of Lamas, told Radioprogramas that power had gone out and that there was some damage to buildings, but no deaths to report.
Police Lt. Gustavo Bustamante in the jungle town of Yurimaguas, 47 miles northwest of Lamas, told the AP there was some physical damage there, but no fatalities.
The earthquake was felt throughout Peru's northern coast and as far away as Bogota, Colombia.
"The quake was felt across Colombia but so far we have received no reports of any injuries or material damage," said Kelly Castano, a spokeswoman for Colombia's National Seismology Center.
Electrical power was temporarily lost in the northern coastal city of Chiclayo, 410 miles northwest of Lima. Airline Lan Peru reported that a passenger jet aborted its landing at the Chiclayo airport because there were no lights on the runway. The plane flew directly to Lima.
It was one of the strongest earthquakes in Peru since a devastating 8.1-magitude temblor hit the Arequipa province in southern Peru in June 2001, killing at least 75 people and leaving tens of thousands homeless. A magnitude-7.6 aftershock struck the southern Andes on July 7, 2001, but did not cause injuries or serious damage.