A 32-year-old multigravida (G3P2) at 39 weeks gestation is admitted to the labour ward in active labour. On admission, cervix is 3 cm dilated, 70% effaced, and the fetal head is at –1 station. A partograph is initiated. Contractions are 3–4 per 10 minutes, each lasting 50 seconds. After 6 hours, the cervix is 5 cm dilated and the head has descended to 0 station. The alert line has been crossed. What is the correct interpretation and management?