New Delhi, Jan 30 (ANI): Congress president Sonia Gandhi and former Prime Minister Manmohan Singh on Friday paid tribute to Mahatma Gandhi on his 67th death anniversary at Rajghat in New Delhi. Prominent leaders from various political parties and other dignitaries are also paying floral tributes at Rajghat. On this day in 1948, Mahatma Gandhi was assassinated at a prayer meeting. The day is also observed as Martyrs' Day as tribute is paid to the martyrs who laid down their life for the nation.