Spanish authorities are warning residents of Lorca not to return to their homes after a pair of earthquakes damaged up to 80 per cent of all structures within the southeastern city.

At least nine people died in the quakes, which struck Wednesday evening and were quickly assessed as being the deadliest temblors to hit Spain in decades.

Freelance reporter Benjamin Jones told CTV's Canada AM that Lorca has suffered at least 30 aftershocks in the hours that have followed the quakes, which has put the city on edge.

"So people are very, very nervous and the authorities are warning people not to return to their homes," Jones told CTV's Canada AM by telephone from Madrid.

In addition to the nine fatalities, 30 people were hospitalized and an additional 2,690 were treated for light injuries and shock.

Scared residents sleep outdoors

Lorca, which lies about five hours southeast of Madrid, has a population of 85,000.

Because of the damage throughout the city, thousands of Lorca residents slept outside after the quake toppled buildings and crushed cars.

"The authorities are trying to assess damage to what they say may be as many as 80 per cent of the homes and buildings in the city and the surrounding region," said Jones.

As dawn broke on Thursday, residents tried to assess the damage of their own properties, with no clue how long it will be before they can return homes.

"You can't imagine how it was," said resident Antonio Galindo.

"Everything was broken, you definitely cannot get in there. You can't even open the door due to all the things that fell down there."

Spanish Prime Minister Jose Luis Rodriguez Zapatero halted campaigning for a set of upcoming elections to oversee an emergency committee tasked with coordinating rescue and relief operations in Lorca.

Zapatero said even with 800 police and soldiers helping clean up the city, it will still take time to get things back to normal.

"We have a lot of work ahead of us," said Zapatero. "The task is very, very intense."

Most quakes in Spain uneventful

Spain typically experiences about 2,500 earthquakes each year, though few are ever noticed by people.

While the quakes that hit Lorca were low in magnitude -- 4.4 and 5.2 respectively -- they both occurred very close to the surface, which amplified their impact on local structures.

"The quakes in this area of the Iberian peninsula tend to be close to the surface. They occur in the first few kilometers of the earth's crust, for that reason they cause more damage," Spanish seismologist Maria Jose Jimenez told The Associated Press.

The U.S. Geological Survey reported different magnitudes for the two quakes, the large one registering a preliminary 5.3 magnitude and the other a 4.5 magnitude.

Since 1999, Lorca has been hit by three quakes of magnitude 5, which caused damage, but no injuries.

With files from The Associated Press