Mata Amritanandamyi Math, better known as "Amma" or "mother," spends most of her time wrapping her arms around crowds of devotees who line up to tap into her spiritual "energy" and has hugged an estimated 20 million people to date.

Tuesday's event in South London was part of Amma's European tour, taking in nine cities, which she hopes will help her take her message of love and spiritual healing to the world.

"I want to flow into the hearts of people and awaken them," she told Reuters in between hugs.

Followers bridge race, religion, class, age and sex and hail from afar afield as India, the United States, Japan and all over Europe. But as they kneel crying at her feet, they agree on the power of this tiny white-robed woman's hug.

Twenty-two-year-old science teacher Vargini Lakshmikan described her first hug: "I was love-struck...it was a deeply moving experience that went to the true essence of me."

A tearful post-hug Linda Broom was overwhelmed: "Something's been lifted, I certainly feel different. I'm spiritually minded but I didn't expect such a deep emotion."

The 47-year-old guru made her first trip to the West in 1987, when only a handful of people would gather to nestle their heads in her lap as she whispered blessings.

But press officer Rob Sidon, who quit his job in marketing to spend more time with Amma, said the guru, who sleeps just two hours a day, draws audiences in India of around 18,000 a day.

"She makes no claims, but she is a living saint," he said. "She is a God-awakened being...no-one's ever seen her yawn -- that's a miracle," he added.