DHAKA, Bangladesh — Crowds of Muslims attacked Hindu homes and temples in eastern Bangladesh this week, raising concerns that the authorities are not taking steps to curb rising religious tensions.

Attacks on Hindus are not unusual in Bangladesh, but it is rare to see multiple crowds targeting temples in an organized way as they did on Sunday and Monday. The country’s human rights commission has initiated an inquiry into the episodes, which the panel’s chairman says appear to have been coordinated.

On Saturday, an Islamic group in Nasirnagar organized a protest against a Facebook post it found offensive. The post included an image of the Hindu god Shiva appearing at a Muslim holy site in the Saudi city of Mecca.

The crowd demanded that the young Hindu man who created the image be put to death. Nevertheless, the group was given permission to hold a rally the next day, and mosque loudspeakers were used to mobilize an even larger group, said Anjan Kumar Deb, the vice chairman of Nasirnagar subdistrict.