An investigation has been launched in France after female staff at the Eiffel Tower were replaced by male colleagues for the visit of a Hindu religious group.

A delegation of around 100 people linked to the Bochasanwasi Akshar Purushottam Swaminarayan Sanstha (BAPS) group visited the iconic landmark in Paris on Saturday.

"Women were asked to leave their places of work" and felt "humiliated", staff union representative Diane Davoine said. The tower closed on Monday as staff went on strike to show their outrage.

BAPS - a movement whose beliefs originate in the 18th Century - strictly separates men and women, including in temple activities and building entrances.

Ariel Weil, who is the president of the company that runs the Eiffel Tower, blamed its managers for being "a bit overzealous" in complying with the request without considering whether it was "inappropriate".

Weil, who is also mayor of Paris Centre, told French broadcaster Franceinfo on Tuesday that the incident was "totally shocking and unacceptable".

An internal investigation will determine who was responsible for putting the conditions in place, Weil said, and ensure it "never happens again".

In a statement reported by AFP news agency, staff at the monument said that during Saturday's visit, female employees were also "instructed not to go through or cross certain areas while the delegation was present".

"Tensions mounted over the weekend, so [on Monday morning], the employees decided to meet: first, to open a dialogue with management, and second, to ensure that women are never treated this way at the company again," Davoine said.

Société d'Exploitation de la tour Eiffel (SETE), which runs the Eiffel Tower, had previously said the conditions imposed on female staff were not in line with its values "nor with the principles of equality between men and women".