More than 240 asylum seekers at a new temporary camp on the Greek island of Lesbos are infected with the novel coronavirus, the public health agency said Monday.

"243 new infections have been discovered" among 7,000 asylum seekers tested, the Eody agency said in a statement.

It added that another tests on 120 police and 40 staff at the camp, which was hastily built last week after Europe's largest migrant camp of Moria was destroyed by fire, had come back negative.

Over 12,000 people including elderly and newborns were left sleeping alongside roads, parling lots and even at the local cemetery when the Moria camp burned down on September 8.

Six young Afghans face arson charges over the incident.

It took over a week for most of the asylum seekers to be rehoused in the new tent camp hurriedly built on a disused army firing range a few kilometres away.

Many migrants were wary of being locked up again after spending months at the notoriously overcrowded and unsanitary Moria camp, where ethnic gang crime was rife.

Since March, movement restrictions at Moria were even more stringent because of the coronavirus pandemic.

Several asylum seekers have now complained that the tents lack even basic bedding and that sanitation is rudimentary.

Another three migrant minors were arrested over a fire that broke out in the asylum seeker camp of Samos Island on Sunday, officials said.

Migration Minister Notis Mitarachi on Monday told parliament that those responsible for the fire would "serve their sentence in Greece and will then be deported”.

Mitarachi said a "modern, safe and respectable” new camp will be constructed on Lesbos — even though local officials strongly oppose the move, demanding the immediate removal of most asylum seekers.

Meanwhile, thousands of people demonstrated Sunday in Berlin and other German cities, urging the European Union to take in migrants left without shelter after a fire destroyed their biggest camp in Greece.

The mask-clad protesters brandishing posters reading "Leave No One Behind” were joined in the German capital by the aunt of Alan Kurdi, the Syrian boy whose image became a tragic symbol of the 2015 refugee crisis after his body washed up on a Turkish beach.

"I decided to speak up and speak for those who can’t speak for themselves... If I can’t save my own family, then let’s save the others”, said Tima Kurdi, urging people to write to politicians to push for action.

"We can’t close our eyes and turn our backs and walk away from them. People are people, no matter where we come from,” she added.

Sonya Bobrik of the activist group Seebruecke also stressed that "we have space” to take in more than the 1,500 refugees now in Greece that Germany has so far promised to welcome.

Police said around 5,000 people turned up at the Berlin rally.

Similar gatherings were seen in Cologne, Munich and Leipzig.

In Paris, around 40 people carrying posters with slogans such as "No One Is Illegal” or "Asylum Is a Human Right” gathered to demand action.

"The situation in the camps is dire”, said protester Nikolai Posner, adding that France is not doing enough to welcome migrants.