What is the Ruling on Praying in an Unjustly Invaded Land?

The strongest opinion of the people of knowledge is that: if a person prays in an illegally seized land, his prayer is valid. (That's) because the prohibition is not on the prayer but rather, it is on the illegal invasion (of the land). So, the prohibition is on something other than the prayer. Therefore, his prayer is valid in this unjustly taken land. However, he is sinning by remaining at this unjustly taken place. If it was narrated from the Messenger of Allah ﷺ that he said, “Don’t pray in an unjustly taken land,” we would have said: if you pray in such land, your prayer is invalid.