The quake struck at 5:16 pm (1616 GMT) with its epicentre at Ossa de Montiel near Albacete, about 220 kilometres (135 miles ) southeast of Madrid, Spain's National Geographic Institute said.
Its depth was given as 14 kilometres (8 miles).
Firefighters in Albacete received several calls for information but not to intervene, a local firefighter service spokesman said.
The last deadly earthquake in Spain occurred on May 11, 2011 when a 5.1-magnitude quake killed nine people and wounded at least 100 in the southeastern city of Lorca.
It was the deadliest earthquake in Spain since April 19, 1956, when a tremor wrecked buildings and left 11 people dead in Albolote, a town in the southern Spanish province of Granada.