The ministry said in a statement on Tuesday that three of the other insurgents killed in the raid were also on a most wanted list of al-Qaida-linked suspects.
It added that two of the men had taken part in an al-Qaida attack on the world's biggest oil-processing plant at Abqaiq in eastern Saudi Arabia last week.
The al-Qaida leader in Saudi Arabia was named as Fahd bin Faraj al-Juwair.
The others were Jaffal al-Shammari, Ibrahim al-Mutair and Abd Allah al-Shammari, while the fifth man was yet to be identified.
An Interior Ministry spokesman said the name of a sixth man who was arrested on Monday would not be released.
Oil facility targetted
The five militants were killed in a dawn shootout on Monday after security forces besieged a villa in an eastern Riyadh area where several Western residential compounds are located.
Riyadh says the men were linked
to an attack on Abqaiq oil plant
The raid took place days after al-Qaida bombers tried to storm the Abqaiq oil facility, in the first direct strike on a Saudi energy target since the group started attacks directed at toppling the US-allied monarchy in 2003.
Tuesday's statement means that almost all of the suspects on a list of 36 issued last year have been killed or arrested.
Security analysts say many others on the list are believed to have joined insurgents fighting in Iraq and some may be dead.