India's Prime Minister Manmohan Singh has undergone successful coronary bypass surgery.
The 76-year-old leader will be in hospital for at least a week and may be able to return to work in a month, doctors involved in his operation said.
Confusion surrounded who was in charge of government as no acting prime minister has been named while Mr Singh is in hospital.
Some officials said Foreign Minister Pranab Mukherjee would take over most prime ministerial responsibilities, including defence, security and the finance portfolio, while Mr Singh was recovering from surgery. However, a government spokesman said the prime minister was still in charge.
His operation came just as his Congress party prepares its re-election campaign for a general election by May.
Mr Singh has been expected to continue as prime minister if the Congress coalition wins the general election. The main battle is between the Congress-led government and a coalition led by the Hindu-nationalist Bharatiya Janata Party.