DHAKA: Bangladesh police said Tuesday they are investigating an e-mail sent to various media organizations reportedly by a banned militant group threatening to topple “towering buildings.”

The e-mail — sent after a series of deadly attacks targeting moderates and foreigners — contains a six-point directive that includes telling women to stay at home. It urges businesses to fire any female employees, and says that working outside of the home is a “punishable offense.” It does not elaborate what would constitute appropriate punishment.

The letter is signed by the group Ansarullah Bangla Team, which is allegedly linked with several other groups that claimed responsibility for killing four atheist bloggers this year.

It threatens to kill more atheist bloggers, naming six in Bangladesh and nine others living abroad to be targeted as soon as they returned to the South Asian country.

It said the list of 15 names is not final, warning that anyone who attempts to degrade Islam would face serious consequences and anyone supporting the atheist bloggers will not “be spared.”

Authorities said they are taking the threat seriously and are investigating. “Higher authorities have been informed,” Dhaka police spokesman Muntasirul Islam told reporters.

The e-mail, received Monday by many Bangladeshi media outlets but not the AP, has renewed concerns about radical forces within Bangladesh.

Since late September, two foreigners — an Italian aid worker and a Japanese agricultural worker — have been gunned down in daylight attacks. Responsibility for both attacks was claimed by Daesh, but the Bangladesh government rejected those claims along with any suggestion that the group was active in the country.