Custodian Abdul Waheed allegedly drugged the victims and stripped them before stabbing and beating them to death.
Police have taken five people in custody, including Waheed and caretaker Yousuf.
Pakistan dargah murder: 20 people drugged, stripped, stabbed
The scene of crime
Locals reported that Waheed and associates would club people who visited the dargah of Muhammad Ali Gujjar in a village in Sargodha of Pakistani Punjab to "cleanse" their sins. The suspect, an employee of the Election Commission of Pakistan, had been visiting since two years.
Rumours abound after horrific murder, heavy police deployment
At least one witness claimed that the events unfolded after a clash over possession of the Dargah. Three people were also injured in the violence and are reportedly critical.
Police were deployed in large numbers in and around the dargah following the incident. A search operation was launched for other suspects.