Carrying dirty things whilst praying

Is it okay to keep things that might be dirty (like handkerchiefs, wallet & car keys) in our pocket while we pray? If not, are we supposed to keep them on the ground in front of us while we pray? Or by the side? Is it okay if it ends up in front of someone else, say in a congregational prayer?

Praise be to Allah, and blessings and peace be upon the Messenger of Allah:

Dirty things are of two types: Things that are considered dirty or unclean according to sharee’ah because of najaasah (impurity), such as human urine or faeces, and things that are considered dirty by people, but they are not naajis according to sharee’ah, such as mucus and spittle. It is not permissible to carry the former or have them on one’s person whilst praying or to put them in the mosque; it does not matter if one carries the latter in one's pocket whilst praying. And Allaah knows best.