The ministry said in the statement that the four online logistics service platforms had problems with repeat charges, price competition, and other irregularities which "damage the legitimate rights and interests of truck drivers".

It said it had urged the platforms to improve the transparency of their business operations, implement reforms to reduce price competition, and maintain a fair environment for market competition.

The companies said they would comply with the recommendations made, the ministry statement said.

The four firms have already seen similar action by the ministry this year, after it also summoned them in January for "operational irregularities."

Chinese authorities have engaged in ongoing crackdown on internet platform companies, which began in earnest in late 2020.

Didi Global has been a major target of the campaign. Earlier this year China's cyberspace regulator levied a $1.2 billion fine on the company for violating data regulations.

That punishment capped a probe that began roughly one year earlier, just as the company listed in New York.

(Reporting by Josh Horwitz and the Beijing newsroom; Editing by Raissa Kasolowsky and Jan Harvey)