 Complete the following phrase:  The whole of IV Corps was now dug in on the Imphal Plain with 17th Indian Division at Imphal in Corps reserve. While the emphasis was on IV Corps efforts to relieve the besieged base at Kohima in the north, 17th Indian Division at Bishenpur on the Tiddim Road was still under pressure from the south. The divisional artillery was disposed in two boxes, most in the north, but with RHQ and three troops of 129th Fd Rgt in the southern box. The gunners themselves had to defend their boxes against attacks by Japanese infantry, as well as firing in support of troops fighting to clear the hills and to counter thrusts by Japanese columns. On 23 June the 