RANGOON - Burmese activists who publicly opposed a controversial interfaith marriage bill say they are receiving violent threats from anonymous callers. At least four activists have been targeted by threats after listing their contact information in early May on a public statement backed by nearly 100 civil society groups that objected to the bill. Since then, they have received anonymous phone calls and online messages threatening violence. One activist was forced to change her phone number after her original digits were posted on a Facebook page advertising prostitutes. Another activist, Aung Myo Min, says he has been urged to stop fighting the interfaith marriage bill, which places restrictions on marriages between Buddhist women and men of any other faith. "Some messages were like, "You will regret it. Stop working for this issue. If you continue, don't blame others for the consequences,'" the director of Equality Myanmar told The Irrawaddy. Khon Ja, a well-known women's rights activist from the Kachin Peace Network, said some anonymous callers have even used phone numbers from Thailand and Malaysia. "They called saying, "If you dare come to Mandalay, you will be dead when we see you," she said, adding that she wondered if the Association to Protect Race and Religion, a radical monk-led group promoting the bill, knew about the threats. Zin Mar Aung, founder of the Rainfall Gender Study Group,says she has received obscene messages on Viber, a phone application. She said one Viber group has been created with the name, "We will kill those who destroy the race." May Sabe Phyu, senior coordinator of the Gender Equality Network, says she is reluctant to connect to the Internet on her phone due to negative messages. "Once I connect, lots of Viber messages come up instantly, with some asking to call so we can talk," she says. Burmese civil society groups have grown increasingly concerned about the interfaith marriage bill, which is part of a package of four bills to protect race and religion. The other three bills would ban polygamy, enact population control measures and restrict religious conversion. The interfaith marriage bill calls for Buddhist women to receive permission from parents and authorities before marrying a man of another faith, who would be forced to convert to Buddhism. Opponents have criticized the bill as undemocratic and discriminatory. Some say it prevents women from making their own choices, while others believe it is intended specifically to prevent conversions to Islam. Aung Myo Min of Equality Myanmar said he is taking precautions with his safety following the threats. "If they are courageous, they need to tell us who they are and why they are doing this," he said of the callers. "It's like they are threatening us from the dark. "Our aim is not to destroy or disrespect race and religion. We also want to protect these. But there are some aims and concepts[in the bill] that we can't accept."