Teen climate activist Greta Thunberg received criticism from the German railway company Deutsche Bahn after claiming her trip aboard a train was overcrowded.

"Traveling on overcrowded trains through Germany. And I’m finally on my way home!" the 16-year-old posted Saturday evening, along with a photo of her sitting on the floor of a train. Thunberg has explained her refusal to travel by air by citing concerns that planes cause environmental damage.

Traveling on overcrowded trains through Germany. And I’m finally on my way home! pic.twitter.com/ssfLCPsR8o — Greta Thunberg (@GretaThunberg) December 14, 2019

"love #Greta , thank you for supporting us railroad workers in the fight against climate change! We were pleased that you were on the ICE 74 with us on Saturday. And with 100 percent green electricity," Deutsche Bahn responded in a Sunday tweet before adding, "It would have been even nicer if you had also reported how friendly and competent you were looked after by our team at your seat in first class."

Noch schöner wäre es gewesen, wenn Du zusätzlich auch berichtet hättest, wie freundlich und kompetent Du von unserem Team an Deinem Sitzplatz in der Ersten Klasse betreut worden bist. #Greta 2/2 — Deutsche Bahn AG (@DB_Presse) December 15, 2019

The company stressed in a statement that Thunberg and her team were in first class for major portions of the trip. Thunberg was traveling from the United Nations climate change conference in Madrid.

"Our train from Basel was taken out of traffic," Thunberg clarified. "So we sat on the floor on 2 different trains. After Göttingen I got a seat.This is no problem of course and I never said it was. Overcrowded trains is a great sign because it means the demand for train travel is high!"

Our train from Basel was taken out of traffic. So we sat on the floor on 2 different trains. After Göttingen I got a seat.This is no problem of course and I never said it was. Overcrowded trains is a great sign because it means the demand for train travel is high! — Greta Thunberg (@GretaThunberg) December 15, 2019

Former United Kingdom Labour Party leader Jeremy Corbyn received similar criticism in 2016 after posting a photo of himself on the floor of a train he claimed was "ram-packed." Founder of Virgin Trains Richard Branson later released footage of Corbyn bypassing several available seats to instead sit on the floor. Representatives for Corbyn later confirmed that he had a seat on his journey.