Taking to microblogging site Twitter, the prime minister said Shastri's "impeccable service" will be remembered for generations to come.
"We pay homage to Shastri Ji on his Punya Tithi. His impeccable service and courageous leadership will be remembered for generations to come," Modi said.
Gandhi invoked the late leader to emphasise the importance of building up unity and solidarity of people.
"Among the major tasks before us, none is of greater importance for our strength and stability than the task of building up the unity and solidarity of our people," the Congress chief said on Twitter.
"My tributes to former Prime Minister Lal Bahadur Shastri ji on his death anniversary," he said.
Shastri was born in 1904 and held office between June, 1964 and January, 1966. He passed away on this day in 1966.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)