Islam orders Muslims to be kind to everyone. Here we would like to stress that there is nothing wrong in attending the funeral of non-Muslims and offering condolences to their family. This should be done to show kindness, mercy, and compassion between the inhabitants of the earth.
Dr. Muzammil H. Siddiqi, president of the Fiqh Council of North America, states the following: We should not put flowers at the grave of anyone, be they Muslim or non-Muslim. It is something that we should refrain from, as it is not something recommended in Islam.