The BBC's Sola Odunfa in Lagos: "Nationwide concern over security at Nigeria's campuses"

The students were shot and clubbed to death in the early hours of Saturday morning when the attackers burst into their rooms at the Obafemi Awolowo University at Ife, about 150 km north-east of Lagos.

The killings were the latest in a series of murders on university campuses in Nigeria, for which the authorities blame clandestine cults whose activities have increased in recent years.

Education Minister Tunde Adeniran issued a statement saying that his ministry viewed the weekend incident with "utmost concern".

"This is a very grave and most intolerable development, especially coming after the government had reassured the nation that the problem of cultism in our tertiary institutions will be tackled with priority attention," he said.

Regional analysts say discipline at Nigeria's universities has deteriorated as academic funding has dwindled.

Violent gangs or cults linked to crime have staked out their turfs on various campuses.

At Obafemi Awolowo University, the students' union has declared three days of mourning for the victims of the weekend's attack

Students on Sunday detained eight suspects whom they said they would hand over to the authorities. They are thought to have collaborated with the killers.