A publisher of primary school math textbooks said it has started to re-do the illustrations they contain after some netizens took issue with them for being ugly and inappropriate.

The People's Education Press said in a statement on Thursday that it has noticed complaints from netizens and will work on improving the illustration style and aesthetic appeal.

It will conduct a comprehensive evaluation of the covers and illustrations in all the textbooks it publishes and improve their design.

The illustrations were a trending topic on social media platforms on Thursday with netizens focused on cartoons of primary school students, which they said had small eyes, strange facial expressions and smiles, with some also wearing strange clothes and making peculiar gestures.

Some netizens said they found the illustrations off-putting and that they did not reflect childish innocence. Others said the illustrations in the textbooks they used were of much higher quality.

The textbooks, which are used by primary school students, were vetted by authorities in 2012 and 2013 and are the work of the Wu Yong Design Studio.

Wu himself graduated from the Academy of Arts and Design at Tsinghua University in 1988. He has worked at China Youth Press and been a professor at Shantou University's Cheung Kong School of Art & Design.

The People's Education Press, founded in 1950, is under the administration of the Ministry of Education and focuses on compiling and publishing textbooks for primary and secondary school students, according to its website.

The statement by the People's Education Press was reposted on the Ministry of Education's official Sina Weibo account on Thursday.

Under recent guidelines, the ministry and four other departments said they would create an accountability mechanism for textbooks to ensure their standardization and quality.