Breaking the protocol for the first time, Indian Prime Minister Manmohan Singh and his wife Gursharan Kaur will receive U.S. President Barack Obama and his wife Michelle at the Delhi airport Sunday, sources here said. Singh and Obama have publicly praised each other on several occasions. Obama hosted the first state dinner of his Presidency for Manmohan Singh in Washington on Nov. 24 last year. "Yes, the Prime Minister and his wife will be receiving the Obamas when they come to Delhi on Sunday afternoon," sources at the Prime Minister's Office (PMO) said. Prime Minister Manmohan Singh is hosting a private dinner Sunday for the U.S. first couple at 7 Race Course Road, his official residence. Also before that, Obama and his family are scheduled to visit Mughal Emperor Humayun's tomb in the afternoon. Barack Obama will also be meeting Congress President Sonia Gandhi and attending a reception by the U.S. Ambassador at the Roosevelt House. Obama is on a four-day visit to India. He arrived in Mumbai Saturday and is to reach New Delhi Sunday afternoon. Earlier on Sunday, Obama and his wife visited a primary school in Mumbai to celebrate the Indian festival Diwali, or festival of lights with schoolchildren. He also attended an e-conference with farmers in Rajasthan and visited an agricultural exhibition at St. Xavier university in Mumbai. Saturday evening, Obama attended a meeting with U.S. and Indian CEOs in Taj Mahal hotel and announced a 10 billion U.S. dollar business deals between the two countries.