BERLIN (AFP) - The nationalist Alternative of Germany was hit by party infighting on Monday (Sept 25) just hours after winning its first seats in parliament, with its co-chief Frauke Petry declaring that she will not join its Bundestag group.

"I decided after careful reflection that I will not sit with the (AfD) parliamentary group" in the Bundestag, Ms Petry told a press conference alongside other key figures in the party before abruptly leaving the room.

Ms Petry, who has long been locked in a dispute with more hardline AfD colleagues, won a seat in Sunday's election and said she would still serve as an MP.

Her decision caught her colleagues by surprise at the press conference, and came a day after the AfD made history by sending dozens of lawmakers to parliament - a first since World War II for an openly anti-immigration and Islamophobic hard-right party.

Ms Petry pointed to "dissent" within the party, and said there was no point hiding that.

She had openly criticised one of the party's two leading candidates, Mr Alexander Gauland, for saying that the AfD would "go after" Chancellor Angela Merkel and her government.

"That is rhetoric that I think... would not be seen as constructive by voters," she told public broadcaster ZDF.

During the campaign, she also said Mr Gauland's claim that Germany should be proud of its World War I and II soldiers would cause voters to shun the party.