Musharraf told local media on Thursday that the suspects would soon go on trial but that the mastermind remained at large.
"There are some people at junior level, people in uniform, air force and army," who have been arrested in connection with the December attacks, the general told Geo Television.
The army chief-cum-president narrowly survived two assassination attempts on 14 December and Christmas Day as his motorcade travelled near his official army residence in Rawalpindi, next to Islamabad.
The mastermind of the attack was Pakistani, said Musharraf, who has enraged Muslim conservatives by working closely with the United States to crack down on Islamist groups fighting an armed struggle in Indian-held Kashmir and Afghanistan.
"We will get him... we know exactly who he is," he said, refusing to name the suspected mastermind.
The military officers detained over the plots will soon be put on trial, he added.
"It will be under a military court and the whole nation will see it," Musharraf said, without giving a date.
In the first attempt, attackers blew up a bridge seconds after Musharraf's car passed over it. On Christmas Day, the bombers rammed two explosives-filled trucks into his passing motorcade, killing 15 people and injuring 46.
Dozens of people were involved in the two plots, he said, and were now in custody.
Musharraf also quietly transferred one his top generals in the powerful Inter Services Intelligence (ISI) spy agency after the second blast.
Seven died when Musharraf's
motorcade was bombed
An intelligence official said the mastermind referred to by Musharraf was a former Islamist fighter from one of the several armed organisations outlawed by Musharraf. He went underground last year.
"Police are searching for him. But he has eluded the hunt so far because he is no longer keeping in touch with his followers," the official, who could not be named, told AFP.
The two truck bombers were identified as Muhammad Jamil and Shafiq Ahmad, both Islamists who fought alongside the Taliban in Afghanistan and against Indian rule in disputed Kashmir.
Jamil was a member of Jaish-e-Muhammad, one of the fiercest guerrilla groups fighting Indian forces in Kashmir. Musharraf outlawed the Jaish in January 2002.
Jamil was captured while fighting alongside the Taliban and jailed in Afghanistan. He was released from an Afghan prison and repatriated to Pakistan just months before trying to kill Musharraf.
Shafiq was linked to Harkat Jihad-e-Islami, an outfit affiliated with Ahmad Umar Said Shaikh, the convicted mastermind of the killing of US Jewish journalist Daniel Pearl after he was abducted while probing the links between Pakistan's secret services and Islamist groups.