 Complete the following phrase:  By now the Axis forces had reacted strongly to the invasion and First Armys drive towards Tunis had been halted in the mountains, with V Corps engaged in hard fighting round Longstop Hill. For the next four months a series of actions was fought along this static line, and an extensive network of signal cables to formation HQs was repaired and laid, despite frequent breaks caused by air raids. 25 Line Section working in the forward areas had to be withdrawn following probes by enemy patrols. Corps Signal Office was established in a storm water culvert under a road, known as The Drain. By May 1943 V Corps was poised for a final advance on Tunis, with the line sections working forwards along the two main axes of advance for 78th Division and 4th Division. Signals personnel helping the Royal Engineers clear minefields along these axes suffered several casualties. Rapid progress was made after Operation Strike was launched on 6 May, and 78th Division entered Tunis on 8 May; V Corps HQ moved up to Massicault the same day. The 