A desperate search is underway for survivors trapped under rubble in the aftermath of an earthquake that has killed at least 21 people in Albania.

Thousands of people have been left homeless and hundreds injured in the most powerful earthquake to hit the small Balkan country in decades.

Residents, some carrying babies, fled apartment buildings in Tirana after the 6.4 magnitude quake struck shortly before 4am on Tuesday (local time).

Two major tremors rocked the capital Tirana and were followed by more than 100 aftershocks, the shakes so powerful they were felt as far away as Italy.

In the nearby northern town of Thumane, Marjana Gjoka, 48, was sleeping in her apartment on the fourth floor of a five-storey building when the quake shattered the two top floors.

“The roof collapsed on our head and I don’t know how we escaped. God helped us,” said Gjoka, whose three-year-old niece was among four people in the apartment when the quake struck.

As of Wednesday morning (Australian time), 45 people had been pulled from the rubble of collapsed buildings. There are hopes more stories of survival will emerge, as soldiers and reinforcements from neighbouring countries join the rescue efforts.

The building shakes in #Shëngjin following the 6.4 magnitude earthquake that struck #Albania. So far, 13 residents have been killed and 600 others injured. – @LastQuake pic.twitter.com/kdWBzLq4IS

— TopInformer News (@topinformer_co) November 26, 2019

The quake was centred 30 kilometres west of Tirana, at a shallow depth of 10 kilometres, the US Geological Survey (USGS) said, and was also felt across the Balkans and in the southern Italian region of Puglia.

Two women were found dead in the rubble of an apartment building in the northern town of Thumane, and a man died in the town of Kurbin after panicking and jumping out of a building, a Defence Ministry spokeswoman said.

The bodies of three other people were pulled from the wreckage of two collapsed buildings in Durres, the defence ministry said, and a man died near the northern town of Lezhe.

Latest reports from Albania on Wednesday (Australian time), said the death toll had risen to 21

Firefighters, police and civilians were removing the debris from collapsed buildings that had trapped people in Thumane.

#earthquake in #Durres
First reported damages! #Albania pic.twitter.com/6jS3Nb0Xiv

— Klaudja Karabolli (@KKarabolli) November 26, 2019

Most of the buildings that collapsed were built from bricks, a Reuters reporter said.

Two people were pulled out from rubble in Thumane four hours after the quake, a Reuters reporter on the site said.

Doctors said they were in bad condition.

Emergency workers told local media one of those killed was an elderly woman who had saved her grandson by cradling him with her body.

The quake was the second powerful tremor to hit the region in two months.

Three hours after the main tremor, a strong aftershock rocked Tirana.

🤲🏼🙏🏻 pic.twitter.com/DTVqNXheqX

— Xherdan Shaqiri (@XS_11official) November 26, 2019

Located along the Adriatic and Ionian Seas, between Greece and Macedonia, Albania experiences regular seismic activity.

An earthquake of 5.6 magnitude shook the country on September 21, damaging around 500 houses and destroying some.

The Defence Ministry had said it was the most powerful quake in Albania in the past 30 years.

-with AAP