Celtic have condemned “sickening” sectarian abuse aimed at Shane Duffy on social media.
The on-loan defender was also taunted over the death of his father on Instagram.
Republic of Ireland international Duffy’s dad Brian died at the age of 53 last May.
Celtic said: “It is disgraceful that Shane should be targeted in this way through such sickening sectarian abuse – and mocking the death of Shane’s father is quite simply despicable.
“This is mindless, vile and abhorrent behaviour and must be challenged and condemned.
“Everything should be done to identify those responsible and the strongest action must be taken.
“Shane of course will receive the full support of everyone at Celtic.”