The force arrived at Kangma on June 23. On the 25th a party of mounted infantry from Gyantse met Captain Peterson's mounted infantry reconnoitring at the monastery of Naini, previously mentioned. Whilst greetings were being exchanged a sudden fire was opened on our men from the monastery, which the enemy had apparently occupied and fortified during the night. The position was apparently held in strength, and the mounted infantry had no other course except to retire to their respective camps. Captain Peterson had one man mortally wounded.
On the evening of the 26th the sentries at the mission post saw about twenty mounted men, followed by two or three hundred infantry, issue from the rear of the jong and creep up the hills on our left in the direction of Naini. It was evident that a determined effort was to be made at the monastery to check the advance of the relief column, which was expected at Gyantse next day. Colonel Brander came to the conclusion that he had found an opportunity for catching the Tibetans in a trap. He determined to send out a force which would block the retreat of the enemy when they retired before the advance of the relief column. Accordingly, before dawn four companies of Pioneers, four guns, and the Maxim gun left the post, and ascended the hills overlooking the monastery. Captain Ottley's mounted infantry were directed to close the road leading directly from Gyantse to the monastery.
Colonel Brander's forces were in position some hours before the mounted infantry of the relief column appeared in sight. It was discovered that the enemy not only held the monastery, but some ruined towers on the hill above, and a cluster of one-storied dwellings in a grove below. Captain Peterson with his mounted infantry appeared in front of the monastery at eleven o'clock. He had with him a company of the 40th Pathans, and his orders were to clear the monastery with this small force, if the enemy made no signs of a stubborn resistance. Otherwise he was to await the arrival of more troops with the mountain-guns.
Peterson delivered his attack from the left, having dismounted his troopers, who, together with the 40th Pathans, were soon very hotly engaged. The troops came under a heavy fire both from the monastery and from a ruined tower above it, but advanced most gallantly. When under the walls of the monastery, they were checked for some time by the difficulty of finding a way in. In the meanwhile, hearing the heavy firing, the General and his Staff, followed by Major Fuller's battery and the rest of the 40th, had hastened up. The battery came into action against the tower, and the 40th rushed up in support of their comrades. Colonel Brander's guns and Maxim on the top of the hill were also brought into play. For nearly an hour a furious cannonade and fusillade raged. Then the Pathans and Peterson's troopers, circling round the walls of the monastery, found a ramp up which they could climb. They swarmed up, and were quickly inside the building. But the Tibetans had realized that their retreat was cut off, and, instead of making a clean bolt for it, only retired slowly from room to room and passage to passage. Two companies of the 23rd were sent up to assist in clearing the monastery. It proved a perfect warren of dark cells and rooms. The Tibetan resistance lasted for over two hours. Bands of desperate swordsmen were found in knots under trap-doors and behind sharp turnings. They would not surrender, and had to be killed by rifle shots fired at a distance of a few feet.