Is it religiously permissible to attend the funeral ceremonies of non-Muslims?

Muslims may attend the funeral ceremonies of non-Muslims for humanitarian purposes such as offering condolences and providing comfort. However, it is not permissible for a Muslim attending such a ceremony to participate in prayers, acts of worship, or other religious rites specific to other faiths, nor to pray for mercy for deceased non-Muslims. When the Messenger of Allah (peace be upon him) visited his uncle Abu Talib on his deathbed, he encouraged him to say “La ilaha illallah,” but when Abu Talib did not accept faith, the Prophet said, “By Allah, I will continue to ask forgiveness for you unless I am forbidden to do so.” Following this event, verse 113 of Surah at-Tawbah was revealed, prohibiting seeking forgiveness for non-Muslims. (Bukhari, Janaiz, 80 [1360])

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu