The Palm Sunday protests have had to take their march to social media following a nationwide ban on large outdoor gatherings.

Supporters are being asked to add a custom frame to their Facebook profile pictures and to post photos of themselves holding up signs to social media, tagged #freetherefugees.

Rally national spokesperson Ian Rintoul said taking the protest online allowed people to raise their concerns but still adhere to laws on social distancing.

"By the time they start sharing their own activities online, it will start to reach many thousands of other people," Mr Rintoul told AAP.

Those not on social media are urged to sign online petitions or put up posters outside their homes on Sunday to lend their voices to those "without a voice".

There are 1440 refugees and asylum seekers in mainland centres.

The Department of Home Affairs says it has increased cleaning of communal, high-traffic areas and common touchpoints in detention centres since the outbreak.

"A range of measures have been introduced, and are being continually reviewed, to keep detainees and staff informed of preventive measures and personal hygiene standards," a Home Affairs spokesperson told AAP on Thursday.

Palm Sunday is a Christian holiday that commemorates Jesus Christ's entrance into Jerusalem and has been used for decades to draw attention to social issues relating to peace.

Australian Associated Press