“And they (the righteous) are those who give food – in spite of their own need, to the needy, and the orphan, and the captive, [saying in their hearts], 'We only feed you for the sake of God, and we desire nothing in return from you, not even a word of thanks'” (Surah Al-Insaan: 8-9).
We find in the Surah Al-Muddaththir a dialogue between the denizens of Jahannam and the dwellers of Jannat who are asking them, what was it that led them to hell?
“What has brought you to this burning abode? They will answer, ‘We were not amongst those who worshipped God (out of arrogance) and nor did we feed the needy….’” (Surah Al-Muddaththir: 42-44)
The Prophet Muhammad SAW said: >"Feed the hungry, visit the sick and set free the captives." (Sahih Bukhari, Volume 7, Hadith 552)
"Beware! Whoever is cruel and hard on a non-Muslim minority, curtails their rights, burdens them with more than they can bear, or takes anything from them against their free will; I (Prophet Muhammad) will complain against the person on the Day of Judgment."
(Abu Dawud)
Please note that neither Allah, the Cherisher of mankind, nor the Prophet Muhammad SAW has forbidden in their orders to feed the non-muslims. There is a hadith describing how we should behave with the Kafir captives. I can't precisely recall that right now, but it goes like this: The Sahabis (followers) were ordered to feed the Kafir captives, let them ride on camels while they are guiding the camels, let the Kafir captives teach the Muslims and set them free after a certain time.