AGRA, India (AFP) - An Indian couple forbidden to marry because of their different backgrounds are in hospital after slitting their own throats in an apparent suicide pact at India's famed monument to love, the Taj Mahal.

Police said the pair - named in the Times of India as Rajveer Singh and Shabnam Ali - were stable after they were discovered in a pool of blood in the grounds of the Taj Mahal on Wednesday afternoon.

"This couple, one of whom is a Hindu and the other a Muslim, tried to commit suicide at the Taj," said police deputy superintendent Aseem Chaudhary.

"The girl cut her throat first followed by the boy."

Marriage outside caste or religion still attracts strong censure in parts of India and can even lead to so-called honour killings, carried out to protect what is seen as family pride.

"Both Shabnam and I tried hard to convince our parents that they should allow us to get married, but the boundaries of religion remained the biggest hurdle," the Times of India quoted Singh as saying.

"We did this after failing at all possible ways to be together."

The Taj - India's top tourist attraction - was built by Mughal emperor Shah Jahan as a tomb for his beloved wife Mumtaz Mahal, who died giving birth in 1631.

It has drawn a string of world leaders and royalty including former US president Bill Clinton, while Diana, the late British princess, was famously photographed alone on a marble seat there in 1992.