ALMATY (Reuters) - Kazakhstan’s foreign ministry summoned the Chinese ambassador on Tuesday to protest over an article saying the country was keen to become part of China, the ministry said.

In a statement the Kazakh ministry said the article titled “Why Kazakhstan is eager to return to China” and published on privately-owned Chinese website sohu.com “runs counter to the spirit of permanent comprehensive strategic partnership” officially declared between the two countries.

The ambassadorial summons is an unusual move since the neighbouring countries usually avoid criticising each other.

The article does not reflect the position of China’s government, and the two countries’ friendship shall not be shaken by any matter, said China’s foreign ministry in a statement sent to Reuters.

The article retells in brief the history of Kazakhstan, noting that leaders of many Kazakh tribes had pledged allegiance to the Chinese emperor.

It also states that Kazakhstan had historically been part of China’s territory and Kazakhs “do not have too many complaints” about being repeatedly invaded by China.

China is a major investor in oil- and metals-rich Kazakhstan and is one of the main markets for its exports, dominated by commodities. Kazakhstan also makes money from Chinese goods carried across its territory to Europe.

But Sino-Kazakh ties have been strained by Beijing’s de-radicalisation campaign in its western Xinjiang province, where the United Nations estimates over a million Muslim Uighurs have been detained in camps.

China has denied the camps violate the rights of ethnic minorities and says they were designed to stamp out terrorism and provide vocational skills.

The Chinese policies have affected ethnic Kazakhs living in Xinjiang, but the Kazakh government has not criticised the campaign and has chosen instead to seek the release of those who had Kazakh citizenship or were seeking it.