Iranian secret police have arrested 19 adherents of the Baha’i faith, in fresh measures against the persecuted religion.

State security agents raided more than 20 homes in the cities of Karaj and Hamedan in Iran’s north and west this week, allegedly assaulting and verbally abusing those taken away.

Tehran has ramped up its persecution of the Baha’is in recent months, arresting 10 women in October and sentencing 26 others to prison.

Similar raids in August saw several leaders arrested on charges of spying for Israel and six homes bulldozed in Iran’s northern Mazandaran province.

The homes of five elderly women were among those raided this week, the Baha’i International Community (BIC) advocacy group said.

One of the women has Alzheimer’s, another was rushed to hospital in distress afterwards and a further two are widows of men executed by the regime in the aftermath of the 1979 revolution.

“What threat do ill and elderly Baha’is pose to the Iranian government?” asked Simin Fahandej, the BIC’s representative to the United Nations. “Nothing but religious prejudice can explain such merciless actions.

“With almost every passing week, and with each new wave of arrests, the Iranian government gives us new proofs [sic] of its cruelty and its intentions to persecute Baha’is only for their beliefs, even in advanced age.”

Iran has released no information about the charges facing those arrested this week or where they are being held.

The Baha’i religion was founded in the 19th century and has frequently been used as a scapegoat when the country is facing internal turmoil or international pressure.

There are about 300,000 Baha’is in Iran and the faith is the country’s largest religious minority.

Its beliefs – which centre on the idea that the founders of the great world religions are all manifestations of the same God – are considered heretical by the Iranian regime.

It often uses the fact that the religion’s headquarters are in the northern Israeli city of Haifa to denounce the faith.

There are estimated to be as many as eight million Baha’i worshippers worldwide, with the largest communities in India, Kenya and the United States.