In great secrecy, India hangs last surviving Mumbai attacker Mohammed Ajmal Kasab

India executed the lone surviving gunman from the 2008 terror attack on Mumbai today, after President Pranab Mukherjee rejected his plea for mercy.

Mohammed Ajmal Kasab, a Pakistani citizen, was one of 10 gunmen who rampaged through the streets of India's financial capital for three days in November 2008, killing 166 people.

Kasab was hanged in secrecy at 7.30am local time at a jail in Pune, a city near Mumbai.

"This is a tribute to all innocent people and police officers who lost their lives in this heinous attack on our nation," said RR Patil, the home minister for the state of Maharashtra, where Mumbai is located.

Indian authorities faced public pressure to execute Kasab quickly and the government fast-tracked the appeal and execution process, which often can take years, or in some cases, decades.

Kasab and the other gunmen entered Mumbai by boat on November 26, 2008. Carrying mobile phones, grenades and automatic weapons, the gunmen fanned out across India's financial capital, targeting luxury hotels, a Jewish centre and the city's main railway station. The three-day attack was broadcast live on television, transfixing the nation and world.

Captured by a photographer striding through Mumbai's main train station, an assault rifle in hand, baby-faced Kasab quickly became the iconic image of the siege.

India blames Laskhar e-Taiba, a militant Pakistani organisation, for orchestrating the attacks. The incident inflamed relations between the nuclear armed neighbours.

An Indian judge sentenced Kasab to death in May 2010 for waging war against India, murder and terrorism, among other charges. Kasab cried as he heard the sentence.