(CNN) A far-right party scored its strongest-ever results in two key state elections in eastern Germany on Sunday, finishing second behind the country's major parties on the same day that Europe marked the 80th anniversary of the Nazi invasion of Poland.
The anti-immigrant Alternative for Deutschland (AfD) party finished second in Saxony to Chancellor Angela Merkel's Christian Democrats (CDU), and second in Brandenburg to the center-left Social Democrats (SPD).
The results represent a blow to Merkel's ruling coalition with the SPD, and will be viewed as a victory for the AfD, which took 27.5% of votes in Saxony and 23.5% in Brandenburg -- a significant increase on state elections five years ago, with the party almost tripling its share in Saxony and doubling it in Brandenburg.
The AfD became the first far-right party to enter Germany's national parliament in almost 60 years when it came in third place overall in federal elections in 2017.
Sunday's results came on the same day that Germany's President Frank-Walter Steinmeier asked Poland for forgiveness 80 years after Nazi Germany's invasion.
The invasion -- on September 1, 1939 -- heralded a dark chapter in Germany history, where some 6 million Jews were killed, almost half of whom were Polish.
Sunday's results prompted some soul-searching in German newspapers about what the rise of the far-right meant for the future of the country.
"These results have brutally demonstrated to political leaders that something is going awry in the country," wrote Deutsche Welle's Editor-in-Chief Ines Pohl. "And they must look and listen more closely to what drives voters into the arms of populists."
Within the last decade the AfD has moved from a euroskeptic party on the fringes of politics, to the largest opposition party in parliament.
In recent years it has shifted focus to migrants and Islam -- directing much of its fury at Merkel's so-called open refugee policy.
The nationalist message has struck a chord in Saxony, Brandenburg, and neighboring states in the former East Germany, where support for the AfD is strongest in the country.
These working class regions, hit by the closure of their coal industries, still lag behind western parts of the country in employment and salaries, making them fertile ground for the far-right. Sunday's results highlight the deep divide that still exists between eastern and western German states almost 30 years after reunification.
Alice Weidel, leader of the AfD's parliamentary party, said the state election results could pave the way for a major shakeup at a national level.
"Our success here could trigger the dismantling of the coalition in Berlin," she said, Reuters reported. "The other parties can't continue with business as usual."
Leading German economist Holger Schmieding believes the governing CDU-SPD coalition will remain largely unchanged.
"Despite spectacular gains in Sunday's state elections, the right-wing AfD did not relegate the SPD in Brandenburg or the CDU in Saxony into second place," he said in a statement.
"In the -- still unlikely -- case of snap federal elections early next year, Germany would probably end up with a CDU/CSU-Green coalition" led by Merkel's successor, Annegret Kramp-Karrenbauer, he said.
In short, the results were "bad" for the major parties, but they "could have been worse," he added.