Shahi Tharoor was schooled by Twitter users after he posted a photo of Nehru and Indira Gandhi.

Congress leader Shashi Tharoor has stepped into a mess with a tweet that was meant as a jibe at Prime Minister Narendra Modi's rockstar outing at Houston for "Howdy, Modi!" He has been schooled by Twitter users for not one, but two mistakes in that post.

Mr Tharoor had tweeted a photo of then prime minister Jawaharlal Nehru and Indira Gandhi, his daughter on a visit abroad. The grainy, sepia-toned photo has Nehru and Indira Gandhi waving to huge crowds from an open jeep.

"Nehru & India Gandhi in the US in 1954. Look at the hugely enthusiastic spontaneous turnout of the American public, without any special PR campaign, NRI crowd management or hyped-up media publicity," Mr Tharoor tweeted.

Nehru & India Gandhi in the US in 1954. Look at the hugely enthusiastic spontaneous turnout of the American public, without any special PR campaign, NRI crowd management or hyped-up media publicity. pic.twitter.com/aLovXvCyRz — Shashi Tharoor (@ShashiTharoor) September 23, 2019

The Congress leader, known for his expansive vocabulary and often mocked over his love for difficult and less-used words, was instantly corrected by users.

"Indira" was misspelt as "India", they pointed out, and the photo was taken in Moscow, not the US. Soon "India" and "Moscow" were trending.

"1) Who is India Gandhi? 2) This picture signifies Congress' 'Parivar-Raj'. 3) It's Moscow not America. 4) It's a well planned "PR campaign". Open car and proper security arrangements. 5) Too many wrongs in one post, Mr. Tharoor," Madhav Sharma, who describes himself as a political observer, tweeted.

"Moscow 1956. More specifically Stalinist Russia, de-stalinisation was yet to go public. Summoning a crowd like this didn't even need PR. #HowdyModi was a triumph. No current Indian leader could have pulled that off... even a dynast. A first generation leader like Modi did it," author Advaita Kala tweeted.

"Shashi says it's USA. BJP trollers say it's Moscow. But it is certainly not orchestrated dance & drama show but a genuine adulation of foreigners for an Indian PM and not just our home crowd. By deriding yr glorious past u are deriding India," senior advocate Vivek Tankha tweeted.

Three hours after the post, Mr Tharoor acknowledged his error, but also defended his comment.

I am told this picture (forwarded to me) probably is from a visit to the USSR and not the US. Even if so, it still doesn't alter the message: the fact is that former PMs also enjoyed popularity abroad. When @narendramodi is honoured, @PMOIndia is honoured; respect is for India. https://t.co/9KQMcR0zTD — Shashi Tharoor (@ShashiTharoor) September 23, 2019

PM Modi's joint appearance with US President Donald Trump at "Howdy, Modi!" in Houston, at a stadium packed with 50,000 Indian Americans, has been described by many as a roaring success but rivals like the Congress have been critical and skeptical about the grand show.

At a party event on Sunday, Mr Tharoor had said: "The Prime Minister deserves respect in foreign countries as (there) he is a representative of our nation. But when he is in India, we have the right to ask him questions."