The New York Times claimed that this was the latest move by the country ahead of the Communist Party congress in Beijing in October.
WhatsApp is owned by Facebook whose main service is blocked on the Chinese mainland. The same applies to the image-sharing app Instagram, also part of Facebook's stable.
In August, it was reported that Facebook had made an attempt to worm its way into China through a photo-sharing app known as Colorful Balloons marketed by a local company.
The NYT report said China had started blocking video chats and sharing of images through WhatsApp in July. These restrictions were lifted after a few weeks.
But now even WhatsApp text messages were broadly disrupted, according to Nadim Kobeissi, an applied cryptographer at Symbolic Software, a research start-up in Paris.
He told the newspaper that the blocking of the text messages indicated that Beijing had developed specialised software to block the messages which use end-to-end encryption.