Former Indian Prime Minister Manmohan Singh was admitted at Delhi-based All India Institute of Medical Sciences (AIIMS) after he complained of chest pain, reported the Press Trust of India (PTI) late on Sunday evening, Trend reports citing Xinhua.
He has been kept under observation at a cardio-thoracic ward, added the report.
Singh, aged 87, was India's premier for ten years from 2004.
Further details were awaited.