The nation will observe the 7th anniversary of the BDR carnage on Thursday, commemorating the atrocious killing of 74 people, including 57 army officials, in BDR (now Border Guard Bangladesh) headquarters at Pilkhana in Dhaka in 2009.Relatives of the martyrs, government high-ups, and Border Guard Bangladesh and army officials paid tributes to the martyrs by placing wreaths at their graves at Banani Graveyard in the city on Thursday morning.To mark the day, special prayers will be offered in all mosques in all regions, sectors, institutions and units of the BGB and at its Pilkhana headquarters and BOPs, seeking divine blessings for the departed souls.Besides, a doa and milad mahfil will be held at Fazlur Rahman Khandaker Auditorium at Pilkhana BGB headquarters at 4:45 pm on Friday.