Despite the one-month ban on visits, relatives can still seek permission to communicate with inmates via the LINE app, to buy goods and to deposit money for them.
During this period, no inmates will be taken outside prisons for work, no inmates will be transferred between prisons and no outsiders will be allowed inside prison grounds.
New inmates will be quarantined for 14-21 days. Hospitals contracted with the Corrections Department will send staff to test new inmates for COVID-19 at least twice before they leave quarantine.
Six COVID cases reported in Surat Thani on Saturday were linked to the Narathiwat outbreak. Five inmates and a warder from Narathiwat had travelled to Surat Thani to attend an anti-drug event at a hotel in Muang district. When they fell ill on Friday, they were tested at a local hospital and the results were positive.
All 143 prisons and correctional facilities throughout the country must strictly comply with this order, except in some cases which may require special approval, Mr Aryut said.
As for the Narathiwat prison, Mr Aryut said he had issued an order to prohibit outsiders from entering and insiders from leaving the prison. Those who had been in close contact with people deemed high-risk had been quarantined.
He said a field hospital had been set up at an old prison for those patients whose infections were asymtomatic or whose symptoms were not serious to isolate them.
Additional swab testing for COVID-19 was being conducted on all those deemed at risk, said Mr Aryut.