Unknown Graves Beside Roskilde Cathedral

Roskilde Cathedral is the burial ground for many of the Danish kings and queens.

However, not all burials took place inside the church and some graves can be seen outside the church walls. The most notable of the burials outside the church is Frederik IX and his wife Queen Ingrid of Sweden.

However, there are also four unknown graves beside the church that are unreadable, but are most likely priests of the church. Behind the church near the Arch of Absalon is the location of five other graves, which I covered here:
http://virtualglobetrotting.com/map/small-cemetery-behind-roskilde-cathedral-1/

The three graves I have located in this map are located beside the small entrance that tourists and visitors of the church walk through to reach the visitor centre near the main entrance into the church that is only used for burials or ceremonies.

Not much is known about these graves and I could find nothing on the internet.