Unaffiliated are world's third largest religious group

The religiously unaffiliated are the third-largest group in the world, after Christians and Muslims, according to a new survey.

About one in six people, or 1.1 billion, profess to having no religious affiliation, according to the Pew Forum on Religious and Public Life. The survey was released on Tuesday.

While the group includes atheists and agnostics, it is not exclusive to them.

"Surveys indicate that many of the unaffiliated hold some religious or spiritual beliefs (such as belief in God or a universal spirit) even though they do not identify with a particular faith," Pew said.

Pew conducted the study, called "The Global Religious Landscape", in 2010 and researched people in more than 230 countries and territories.

The survey found there were 2.2 billion Christians, about 32 percent of the world's population, and 1.6 billion Muslims.

The fourth-largest group in the world were Hindus, about one billion, followed by about 500 million Buddhists.

More than 400 million, or six percent, of the world's population practice different folk or traditional religions, including African traditional religions.

The survey found about 14 million Jews, about 0.2 percent of the population.

About 58 million people, less than one percent of the population, practice other religions including Baha'i, Jainism, Sikhism, Shitoism, Taoism, Tenrikyo, Wiccanism and Zoroasterianism, amongst others.