[4] They were also part of the first generation of PLAN warships armed with surface-to-air missiles in the form of the short-range Crotale (called HQ-7 in Chinese service.

The embargo after the 1989 Tiananmen Square protests and massacre ended the supply of and support for those subsystems, limiting production to two ships[4] and likely affecting their operating efficiency due to system integration issues.

[4] The CDS, possible the ZKJ-6 based on the Italian IPN-10 or IPN-20,[9] began development in 1983 and underwent land-based testing in December 1986.

[1] A major refit began in 2010 for Harbin and Qingdao in 2011 which included changes to sensors and weapons, gas turbine replacement, and some hull work.

[1] The ships were completed with different gas turbines due to the embargo; Harbin with two General Electric LM2500s from the United States, and Qingdao with two Zorya-Mashproekt DA80s from Ukraine.

Observations by foreign visitors to Harbin in March 1997 suggested limited damage control capability and crew safety features.