KABUL – Turkish authorities may have deported as many as 30 Afghans just hours after the European Union signed an agreement designating Turkey as a “safe” country for refugees, according to the London-based rights group Amnesty International.

The March 18 agreement between E.U. and Turkish officials calls for the return of asylum seekers to Turkey en masse – once their asylum claims have been processed – in exchange for 6 billion euros (or about $6.7 billion) in aid and potential visa-free travel for Turks across Europe. The deal also labels Turkey a safe country for refugees, meaning there is no threat of serious harm to asylum seekers and that the government will not return refugees or migrants to unsafe countries.

But Amnesty International said on Wednesday that Turkish authorities detained at least 27 Afghans in the northern city of Izmir this month and forced them to board a flight to Kabul on March 18 without allowing them to access any type of asylum procedure. Their alleged return to Afghanistan, which has seen a rise in conflict-related violence, would violate European and international law, Amnesty says, and is a clear abuse of refugee rights.

“Returns to Turkey cannot proceed on the basis that Turkey is a safe country for refugees,” John Dalhuisen, Amnesty’s director for Europe and Central Asia, said in a statement Wednesday.

The Turkish government confirmed to Amnesty that around 30 Afghans had returned this month but said they had done so voluntarily. In February, 125 Afghans agreed to return to Kabul from Germany on a special charter flight.

“The ink wasn’t even dry on the E.U.-Turkey deal when several dozen Afghans were forced back to a country where their lives could be in danger,” Dalhuisen said. “It’s like watching a train wreck in slow motion.”

Nearly 180,000 Afghans requested asylum in European countries last year, according to E.U. figures. And Afghans are now the second-largest group of asylum seekers in Europe after Syrians.

But in December, Germany, which has accepted more than 1 million refugees and migrants, announced a blanket ban on Afghan asylum seekers. Authorities said most were fleeing poverty. Germany’s declaration may have signaled to Turkey that it could deport Afghans without any repercussions under the new agreement, an Afghan migration expert said. The expert spoke in the condition of anonymity because of the sensitivity of the subject.

Turkey has also deported Syrians, according to a December report by Amnesty International. The E.U.-Turkey agreement says that asylum applications processed in Europe can now be rejected if it is determined that the applicant could have applied for protection in Turkey or already had protection there.