A Kabul-bound plane with 18 Afghan migrants on board took off from Munich Airport late Wednesday, its passengers becoming the third group of rejected asylum seekers to be deported by German authorities back to Afghanistan.
The deportations have come under fire in Germany from opposition parties and rights groups who argue that much of Afghanistan is not safe for return.
The Bavarian Interior Ministry reported there were 18 deportees on board - fewer than the 50 previously cited by Upper Bavarian police.
Around 250 people gathered at the airport to protest the deportation, according to police.
"This is unjustifiable," said Maria Brand, an aid worker from Upper Bavaria's city of Erding.
"There are no secure areas in Afghanistan," said Nadine Kriebel of the Bavarian Refugees' Council, which organized the rally. "We want to lodge a protest against these indiscriminate deportations."
In the past, the majority of Afghans whose asylum bids were declined were allowed to remain in Germany due to the security threat in their country. But Berlin decided last year to designate parts of Afghanistan safe for return.
German Interior Minister Thomas de Maiziere said in October that the group deportations were supposed to send a signal to Afghans that Germany only accepts a small number of asylum bids from their country.
Peter Altmaier, German Chancellor Angela Merkel's chief of staff, defended the initiative on Wednesday, saying that the authorities had to act on decisions made by the courts.
"Those who have no claim to asylum from any conceivable point of view - where the courts have determined that they do not face the threat of persecution - must expect to be repatriated," Altmaier told Deutschlandfunk radio.