[3][4] After initial success over Pakistani troops, there had been some relative calm in the region, and further Indian assistance was sought to turn the tide.

Economically burdened by nearly 10 million Bangladeshi refugees,[5][6][7] India thus started to involve itself deeper into the conflict brewing in the east and stationed its troops near the border.

On 21 November, the 14 Punjab Battalion, supported by PT-76 tanks from 45 Cavalry and the Mukti Bahini, moved in to capture the areas around Garibpur inside the Pakistani territory.

The move was supposed to be a surprise, but a skirmish between patrol troops of both armies the previous day had caused Pakistan to be alerted to the impending attack.

Pakistan immediately retaliated with its infantry battalion supported by 3rd Independent Armoured Squadron, equipped with M24 Chaffee light tanks.

[9] Retaining the infantry and the recoilless rifles in a defensive position, the Indian tanks were sent forward to ambush the oncoming Pakistani charge.

[1][10] The Pakistani Air Force Contingent in Dhaka responded by launching several sorties of Canadair Sabre Mk6s from the morning of 22 November 1971, which set the stage for the Battle of Boyra.

However, it was common for Bengalis in the Pakistan Armed Forces to defect and to join the Mukti Bahini or to be grounded or removed from positions of authority during the war because of suspected loyalty[8] and so that was a likely reason.

As the Gnats dived in, a section of two Sabres pulled out of the attack and placed themselves in an awkward position, just in front of Ganapathy and Lazarus.

The Pakistani pilots (Parvaiz Mehdi Qureshi and Khaleel Ahmed) ejected over Boyra and parachuted down safely but were taken as prisoners-of-war.

The Sabre pilot, Wing Commander Chaudhury, in a skilful dogfighting move broke into Massey's attack and forced him to take a high angle-off burst, which missed his target.

After manoeuvring back into firing position and taking aim, Massey let off another burst at 700 yards (640 m) and hit him in the port wing.

Massey realised that he was well over East Pakistani airspace in his chase and turned around and regrouped with the rest of his formation, which then proceeded back to base.