The death toll in a sectarian clash in northwest Pakistan rose to seven today as some persons succumbed to injuries sustained in the fighting.A total of 35 people were also injured in the clash yesterday in Dera Ismail Khan district between two groups.Members of the two groups scuffled and then exchanged fire.Police arrested 165 people from both groups and put them behind bars and imposed a curfew in the area.They also raided the homes of those involved in the violence.Local residents described the situation in the area as tense.