Since the beginning of the Cultural Revolution and Mao Zedong's support for leftist "rebellion", some "rebels" who had been suppressed by the army used the opportunity to attack the army. On January 28, 1967, the Central Military Commission (CMC), seeking to stabilize the army against such attack and to provide the army with a basis for suppressing the more Mao-leaning "rebels", issued the "Eight Point Order". This Order required that the military take dictatorial measures against those proven by evidence to be counter-revolutionaries (i.e., Mao's "rebels"). Between February and May, 1967, millions of these "rebels" were arrested across the country; the brutality far exceeded the Campaign to Suppress Counter-revolutionaries of the early 1950s. Within this, the February 23rd Qinghai Incident is regarded as a well-known instance of mass killing.

In 1961, Zhou Enlai had sent Wang Zhao, deputy minister of the Ministry of Public Security, to Qinghai to assume twin positions there as Governor and as Second Secretary. However, Wang was not up to the task of handling issues brought on by the Great Famine and the Four Cleanups Movement, and harmed many people as a result. In the years before the Cultural Revolution, many of these people were subsequently rehabilitated. Wang thus became a target for overthrow by the "rebel" camp.

In 1966, the "Qinghai Daily" newspaper published the editorial "Great Offensive, Great Counter-Offensive, Great Revolution", calling on the masses to follow Mao's rhetoric and rebel. By August, the masses in Qinghai had divided into two factions. The first was the "Qinghai 8.18 Revolutionary Rebellion Headquarters" (or "8.18" for short), which was resolutely determined to take down Wang Zhao. The more conservative faction included several groups, such as the "Red Guards Headquarters", "Poor and Lower-Middle Peasant Red Guards", and the "Battle Squad for the Defense of Mao Zedong Thought". These two factions, "rebel" and "conservative", stood at odds with each other.

In January 1967, rebels in Shanghai had seized power from the Party and government organizations to form the Shanghai Commune. The 8.18 faction in Qinghai took inspiration from this, and took over the "Qinghai Daily"; the Chinese Communist Party (CCP) Central Committee also sent troops as an expression of support. However, there were differences within the provincial military region leadership: Commander Liu Xianquan expressed support, while Deputy Commander Zhao Yongfu and several cadres were opposed to the 8.18 faction. Later, Zhao sent subordinates to put Liu Xianquan under house arrest and gained the upper hand.

"Qinghai Daily" was creating massive public support for 8.18; Zhao Yongfu therefore began plan how to use the army to forcibly take over the newspaper office and launch an armed demonstration to "support the revolutionaries and suppress the counter-revolutionaries". On February 14, Zhao decided to take military control of the "Qinghai Daily" office; he sent a military management team there to take over. The two sides faced off in the newspaper office for several days. The provincial military command sent a telegram to the CMC, saying that the 8.18 group was in the newspaper office "making a great effort to destroy guns and shout counter-revolutionary slogans."

On February 23, the provincial military region leadership attacked "Qinghai Daily" headquarters with 13 companies of soldiers; later that day, gunfire broke out. The army killed 169 rebels and wounded 178. Zhao Yongfu later reported the news: "An organization formed by the masses in Xining City, called the '8.18', created an armed riot. They were first to shoot and kill cadres and soldiers. The army fought back in self-defense; the riot has now been quelled." Over 10,000 people were arrested, detained, placed under guard, or placed under house arrest during the capturing of the 8.18 faction.

However, this was not the end of the matter. In March, the CCP Central Committee received a large number of letters and visits from the masses. Mao Zedong and Lin Biao gave instructions to thoroughly investigate what had happened in Qinghai. Finally, it was confirmed that the 8.18 in the "Qinghai Daily" offices had been unarmed. On March 24, at a meeting to handle the February 23 Incident, Zhou Enlai read out the "Decision of the CCP Central Committee, State Council, CMC, and the Central Cultural Revolution Group on the Qinghai Issue". The Decision said that Zhao Yongfu had used conspiratorial methods to usurp Comrade Liu Xianquan's military power. Zhao's actions constituted a "counter-revolutionary coup" within the provincial military district leadership. The Decision also ordered the release of revolutionary masses who had been arrested.

The reversal of the February 23 Incident's conclusions had a demonstrative effect in many places. Many suppressed members of the rebel camp rose up to demand vindication, and started a new round of attacks against the regional military leaders.

References: Yang Jisheng, "The World Turned Upside Down: A History of the Chinese Cultural Revolution"; Bu Weihua, "History of the People's Republic of China: Smashing the Old World — Turmoil and Catastrophe in the Cultural Revolution (1966-1968)"