While military officials insist that toppling of Sharif came as a total surprise, The News, a leading English daily, said on Wednesday that the army had already chalked out a plan of action that would come into effect should Sharif sack the army chief.

The strained relations between Sharif and Musharraf came into the public eye earlier this week when the army chief, a Mohajir, ordered the retirement of Lt Gen Tariq Pervaiz, the Quetta army commander, after Pervaiz bypassed Musharraf to meet the PM, who was looking for possible replacements for the army chief.

The tension between the PM and Chief of Army Staff (COAS) dates back to Sharif's visit to Washington where he agreed to pull out Pakistan-backed militants from Kargil withoutconsulting the military leadership. Musharraf was livid. The leader of the military coup in Pakistan is a former army commando known to be a moderate in domestic affairs, but a hawk when it comes to Pakistan's volatile relations with India.

Sharif planned to lull Musharraf into complacency before sacking him, say military sources. This he did by agreeing to the ouster of Lt Gen Pervaiz, giving Musharraf the impression that he still enjoyed the confidence of the PM. A week before, Sharif had given Musharraf the charge of Chief of the Joint Chiefs of Staff Committee in addition to his job as COAS, which prompted the resignation of the naval chief, Admiral Fasih Bokhari, who protested against this move.

But Sharif had other plans for Musharraf. He had decided to sack him and appoint Lt Gen Khawaja Ziauddin Butt, the chief of the ISI in his place. Butt, a fellow-Punjabi who shared Sharif's Kashmiri origins, however, was not acceptable to the military command for a very simple reason: he was junior to most ofthe army corps commanders, and had he been appointed, a number of them would have had to call it a day.

It was not Gen Musharraf who initiated military action in the country, say sources. Instead, the first step was taken by the corps commander of Rawalpindi, the army headquarters. He had key installations in the capital and the PM's office and residence surrounded.

Musharraf was on his way to Pakistan from Sri Lanka. When the army moved in, the prime minister's office told Karachi airport to not allow the commercial flight to land ``at any cost''. The Sharif camp planned to make the plane land at Nawabshah, an airport in Sindh province, and have Musharraf arrested. Some sources say that instructions had been given by the PM to fly out a plane to bring in Musharraf to Islamabad. This move would have foiled the army's plans.

Sensing this, the corps commander of Karachi and also a Mohajir, Lt Gen Salahuddin Tirmizi, had his troops move into Karachi airport and take over the building, forcing thecommercial flight to finally land at Karachi.

As Musharraf alighted, he was rushed to the corps headquarters, Karachi, where he planned his strategy with fellow commanders. After addressing the nation at 3 am from this building, Musharraf left for Islamabad from Karachi, while the military held on to the Karachi airport and Islamabad airport. A decorated soldier, General Musharraf wore commando fatigues instead of his military dress uniform on national television to announce that Sharif had been overthrown.

Musharraf joined the military in 1964 and served twice in Pakistan's Special Services Group or commando unit. He confronted Indian soldiers as a commando stationed on the disputed border with India in Kashmir.

According to most western analysts, Musharraf orchestrated the occupation this summer of Indian territory in Kashmir by Islamic militants.