LAHORE On completion of one year of the Data Darbar tragedy, parties from Ahle Sunnah school of thought will observe Youm-e-Shuhada Data Darbar on Friday. During Juma prayers, ulema and khatibs will deliver special sermon on the tragedy and will condemn the suicide attacks and those patronising the heinous act. After the Juma prayers, rallies and demonstrations will be held outside mosques to condemn and protest against the incident.