The woman left a severed pig’s head outside the mosque and Islamic-cultural center in City Blue area of Warsaw, IINA reported.
The 40-year-old radical woman is a member of an extremist group, reports said.
Police said that the move was a crime and that the perpetrator will be detained for insulting the religious sanctities of Muslims.
The mosque had just been inaugurated at the beginning of the holy fasting month of Ramadan (July 17).
It is the second mosque in Warsaw and its construction had faced many hurdles and problems.
Islamophobia has been on the rise across Europe during the past few months, especially after an attack against the French satirical magazine Charlie Hebdo earlier this year.
Islamophobia is a term used to describe irrational hostility, fear, or hatred of Islam, Muslims, and Islamic culture, and active discrimination against these groups or individuals within them.
Today, Islamophobia in Europe manifests itself through individual attitudes and behaviors, and the policies and practices of organizations and institutions.