IPOH, March 7 -- Housing and Local Government Minister Nga Kor Ming's mother received anonymous threatening letters in front of her house in Ayer Tawar warning him to not "challenge Islam", police have said.

Manjung police district chief ACP Mohamed Nordin Abdullah said today that Nga's mother, 76, made a police report over the incident at around 10.15am today.

"The woman, who is a retiree, noticed various letters in front of her house warning Nga to not challenge Islam when she wanted to leave the house at 7.30am today.

"The complainer believed that the words in the letters have bad intentions," he said in a statement.

It is unsure what prompted the threats.

Mohamed Nordin said the case is being investigated under Section 507 of the...