India celebrated its 61st Republic Day on Tuesday.

Prime Minister Manmohan Singh paid tributes to war heroes at a memorial in New Delhi.

This year, South Korean President Lee Myung-bak is the honorary guest at the parade.

He watched tanks and armored cars roll by and fighter jets roar over thousands of people attending the celebrations.

Several Indian ministers along with the Indian president and prime minister stood tall as the Indian flag was hoisted in the backdrop of the national anthem.

Security was also tight around the country. Cities, railways and airports in many parts of the country stepped up vigilance… warry of militant attacks.

The air force was also put on high alert after agencies warned of a possible air attack by Lashkar-e-Taiba, the Pakistan-based militant group blamed for the November 2008 Mumbai attacks.

Troops intensified patrols and searches in states affected by separatist and Maoist insurgencies.

India became a republic on January 26, 1950, and celebrates the day every year with military parades, pomp and ceremony in all major cities.