By Rajeev Khanna
BBC News, Dwarka, Gujarat
Two senior leaders of India's main opposition Bharatiya Janata Party (BJP) have embarked on what they say is a nation-wide security tour.
Mr Advani says the Congress party is appeasing Muslims for votes
Senior leader LK Advani and BJP president Rajnath Singh are leading two separate tours.
The BJP says it also wants to protest against what it says is the appeasement of Muslim minorities by the ruling Congress party.
The campaign follows a recent bomb attack on a Hindu temple in Varanasi.
Nearly 20,000 BJP supporters gathered as Mr Advani kicked off the Bharat Suraksha Yatra (India Security March) as the tour is called, in the Hindu holy town of Dwarka in the western state of Gujarat.
In a speech, Mr Advani attacked the Congress party-led Indian government which he said was "resorting to minority appeasement to gain their votes".
He also called on the Muslim community to give up its claim on a disputed site in the northern town of Ayodhya, to make way for the construction of a Hindu temple there.
"They [Muslims] should understand that millions of Indians want a temple at the site,'' Mr Advani told the crowd.
A mosque at the disputed site in Ayodhya was torn down by Hindu zealots in 1992.
Gujarat Chief Minister Narendra Modi, who was also present at the launch, attacked the federal government for setting up its own investigation into a fire on a train at Godhra that killed 59 Hindu pilgrims in February 2002.
The BJP alleges that the train was fire-bombed by a Muslim mob - but a recent federal inquiry said there was no evidence to suggest this.
The deaths of the pilgrims was followed by large-scale riots across Gujarat in which more than 1,000 people, mostly Muslim, died.
Mr Modi's government was widely blamed for doing little to prevent the riots.
The second tour was inaugurated by BJP President Rajnath Singh from Bhubaneshwar in the eastern state of Orissa.
The crowd at both the venues was less than anticipated.
Mr Advani has undertaken such nationwide tours in the past.
A similar tour in 1988 to rally support over the Ayodhya issue helped the BJP electorally, as it grew to become one of the biggest parties in parliament.
Analysts say the BJP is hoping that the twin tours will lead to similar gains.