Col. Ernesto Boac, commander of the Army’s 401st Infantry Brigade, identified the three as a certain Abdulkhair, Jamil and Samad.
But Dr. Camar Umpa, MSU president, denied that the suspects were former members of the university’s security force.
"As far as I know, those names are not in our list of security personnel," he said.
Boac said the three remain as suspects because investigators have yet to corroborate earlier reports.
"We cannot link these suspects to the notorious Pentagon gang as speculated by other people. Anyway, the intelligence reports will still be corroborated," he said.
"The negotiators have to make contact with the kidnappers so that we will know what their demands are," he added.
Quoting information from his men and local leaders, Lanao del Sur Gov. Mamintal Adiong said the suspects could be disgruntled former security men of MSU who have been terminated and not paid their wages.
"We have to address this properly, they cannot just kidnap anybody to get their demands," he said.
Boac said the kidnappers are demanding a P2-million ransom for the freedom of the four teachers — Salvacion Mikim, 55; Luzvilla Serete Castillon, 53; Emma Manzano Cara-an, 43; and Editha Bontilao, 50. — With Roel Pareño