Hong Kong Reverend Chu Yiu-Ming has played many roles in social movements: He is one of the Occupy Central Trio; he was a member of the original Hong Kong Alliance in Support of Patriotic Democratic Movements of China standing committee; and he was also one of the main implementers of 1989's Operation Yellowbird.

June 3rd, 1989, Chu Yiu-Ming had just returned from bringing supplies to Beijing on behalf of the people of Hong Kong. At a friend's wedding, he learned that gunfire had erupted in Muxidi, Beijing. By the middle of June, Chu learned that an 'underground railroad' had been started, helping to rescue student leaders and democracy advocates who had been listed as wanted for arrest. By the end of June, at the invitation of Szeto Wah (who was then serving as chair of the Alliance), Chu began participating in the rescue operation. As the rescues were going on, Chu was primarily in charge of traveling to different consulates and lobbying.

In a media interview, he once detailed his participation in the rescue efforts: "The most important thing in helping them [the June 4th refugees], the first thing, was to talk with the Hong Kong government… If we could prove that they had connections to the democracy movement, the government would issue them a 'Recognizance Form No. 8', which is a kind of temporary permit to remain in Hong Kong. That way, they were legal. In most circumstances, it gave them three months; and in those three months, we could lobby other countries to take them in. The second step was traveling to the consulates, and hoping they would accept. We had to do that because France had already taken in so many… and they didn't have the capacity to take care of that many people. We started to look for places where they could live. Once they had been inspected at immigration, they could stay in the houses we found and wait for other countries to accept them… The third step was going to find Chinese citizens' groups in other countries, such as the US, Canada, etc., that Hong Kong emigrants had joined, and churches."

As Chu recounts it, from the end of July to August, 1989, about 70 or 80 people stopped off in Hong Kong. Because France had taken in too many refugees, the group was facing immense political pressure. Luckily, at the beginning of September, the US expressed willingness to accept the exiles. At that point, the 'underground railroad' for June 4th exiles was officially open.

Reference: Radio France International (RFI) https://www.rfi.fr/tw/港澳台/20190611-朱耀明牧師與黃雀行動港人做了一件很光榮的事 Reverend Chu Yiu-Ming Reverend and Operation Yellowbird Did a Glorious Thing)