American women are being targeted by members of the Islamic State (IS) in Syria, who promise money in return for bearing children for militants, the Times reports.

Around 130 westerners are thought to have been recruited by extremists who primarily use social media to target vulnerable women.

Female members of at least three Somali families in Minneapolis, Minnesota, have gone missing in the past six weeks, in addition to a 19-year-old from the same area who is known to have flown to Turkey in secret before crossing the border into Syria.

A second 19-year-old, Shannon Conley from Denver, Colorado, last week pleaded guilty to conspiring to provide material support to IS.

She was arrested in April as she attempted to board a flight to meet  a Tunisian IS militant whom she had met online. The man had proposed, and asked Conley to join him in fighting with the terrorist organisation.

According to documentation from the case, Conley told FBI agents that she had planned to use her nursing training to help IS militants, and officials found CDs with teachings by radical Muslim cleric Anwar al-Awlaki among her belongings.

The Times reports that the Twin Cities area of Minnesota, which is home to the largest Somali community in the US, has been "plagued by terrorist recruiting" in recent years.

US citizen Douglas McAuthur McCain, who was killed in battle alongside IS in Syria last month, was one of an estimated 15-20 men fighting in the area with links to the Minnesotan Somali community.

Having grown up in the state, McCain converted to Islam from Christianity a decade ago according to his Twitter account, where he wrote that this decision was "the best thing that ever happen to me" [sic].

Of the new drive for female recruits, professor at the centre for terrorism and security studies at the University of Massachusetts, Lowell, Mia Bloom said: "They are selling them this mystical sisterhood of going to the caliphate and being able to be a Muslim in this idealised, utopian society.

"They are targeting these young girls in a very predatory way – the way child sex abusers target young children."

Young women are apparent offered cash for each child they can produce, as well as other 'benefits'. Those of "prime fertility age" are usually recruited, and are usually used to cook and clean – despite often being promised the glory of fighting alongside militants.

There are now concerns that women may be targeted for use as suicide bombers, however.

Bloom said they are "ideal for targeting civilians" as they are less conspicuous in a public setting.

"Until recently, Isis has been attacking soldiers – a woman is going to stand out like a sore thumb there," she explained.

"Whereas if you change your tactics and target mosques or schools, that's when women are really quite ideal."