Veteran BJP leader Lal Krishna Advani was admitted to the Apollo Hospital here on Wednesday night, sources said.
This comes days after the 96-year-old former deputy prime minister was discharged from the All India Institute of Medical Sciences (Aiims) after a night-long stay there.
"Advani is stable and under observation. He has been admitted under Dr Vinit Suri, senior consultant, Neurology," a hospital source said, adding that he was admitted around 9 pm.
The details of Advani's ailment were not known immediately.
He was born in Karachi (present-day Pakistan) on November 8, 1927, and joined the Rashtriya Swayamsevak Sangh (RSS) as a Swayamsevak in 1942. He served as the Bharatiya Janata Party (BJP) National President from 1986 to 1990, then from 1993 to 1998, and again from 2004 to 2005. Advani held the position of party President for the longest duration since its inception in 1980.
Over nearly three decades in Parliament, Advani served first as the Home Minister and later as the Deputy Prime Minister in Atal Bihari Vajpayee's cabinet from 1999 to 2004.
In the lead-up to the 2009 elections, as the Leader of the Opposition in a parliamentary democracy, Advani was considered the BJP's Prime Ministerial candidate for the general elections, concluding on May 16, 2009, according to the BJP's official website. On December 10, 2007, the BJP's Parliamentary Board formally announced Advani as its Prime Ministerial candidate for the 2009 general elections. However, when the Congress party and its allies won the 2009 general elections, Advani stepped aside for Sushma Swaraj to become the Leader of the Opposition in the 15th Lok Sabha.