Several young officers with the Pakistani Air Force with access to President Pervez Musharraf's innermost security circle were among 50 people arrested for trying to assassinate him soon afte he returned from a visit to the US and Britain in late September, a report said on Sunday.
The rocket strike was aimed at the President's high-security personal residence-office in Rawalpindi.
"About 50 people are being held on suspicion of involvement in the September attack, which involved a battery of Russian-made 107 m projectiles launched by a signal from a mobile phone," Pakistani intelligence sources were quoted as saying by The Sunday Telegraph.
"Alarmingly, many are understood to be young officers serving in the Pakistan Air Force, some of whom have access to high-security zones of the presidential offices, parliament and the intelligence service," they said.
Although interrogations have not revealed any of them to have links with al-Qaeda or the Taliban, they are none the less believed to have acted out of growing anger at Gen Musharraf's alliance with America in its war on terror.
One official said that while the rocket strike itself had been relatively amateurish, it would have probably been lethal had the plotters been assisted beforehand by an Islamic terrorist group.
Although the president was not hurt, the attempt demonstrated the political instability engulfing his nation, which was heightened last week by his government's bombing of a madrassa in north-west Pakistan, the report said.
A rattled Gen Musharraf has called a meeting with his closest confidants this week to review personal security.
While Musharraf relies on the armed forces to keep him in power, loyalty among the military's lower tiers has become increasingly in doubt because of the perception that he has "sold out" Pakistan to the US and its western allies, the report said.
Publicly, officials close to the president deny that he faces any challenge from within the forces. But privately they now admit that the personal threat against him is becoming "heavier and heavier" and are predicting serious fall-out from the latest helicopter strike at the madrassa in the village of Chinagai, 160 km north of Peshawar.
The Pakistani army said the madrassa was an al-Qaeda-linked school, used to train insurgents fighting across the border in Afghanistan.
It was allegedly run by Liaquat Hussain, a fugitive cleric who was a purported associate of al-Qaeda's second in command leader Ayman al-Zawahiri. Residents and local religious parties, however, claim the victims were either innocent Islamic students or teachers. They say that the strike was carried out at the direction of the US military, a claim denied by both Islamabad and Washington.
The madrassa was in the Bajaur province, a tribal area where local religious parties openly support the Taliban. Local leaders have already pledged to carry out suicide attacks to "avenge" the killing of "innocent people".
"The elimination of Musharraf is a must to restore peace," declared Maulana Faqir Muhammad, a pro-Taliban militant commander, as a crowd carrying guns and chanting "Death to Musharraf, death to Bush" protested in the Khar area of Bajaur last week. He described Gen Musharraf as an "American agent" who was "killing innocent people at the US behest".