Hundreds of protesters chanting “Free Hong Kong!” filled the Hong Kong International Airport on Friday, seeking attention from international arrivals and demanding a thorough investigation of last Sunday’s mob attack on activists at a train station.

“The world has been watching us in the past few weeks. We simply believe that the airport is the most direct way for all tourists to explain what is happening in Hong Kong,” said demonstration organizer Jeremy Tam, a former airline pilot who currently serves in the legislature as a member of the Civic Party.

Channel News Asia observed the demonstrators employing some clever techniques to get the attention of airport patrons:

One particularly creative group of protesters used a television to display a satirical version of an airline safety announcement video that details protester demands and warns of protests in the city.

“Kindly put on your masks and black t-shirts … when attending the assemblies,” the video said, in a reference to the colour widely adopted by anti-government protesters.

Others held “Tourist Warning” signs detailing how police have fired tear gas at protesters while pro-government thugs have also attacked demonstrators, putting 45 in hospital.

One clever protest sign was made to look like a flight status update, announcing the arrival of “Flight 726” (a reference to Friday’s date, 7/26) from Hong Kong at its final destination of “freedom.” Another mock flight announcement informed Carrie Lam that her flight to “hell” was now boarding.

The UK Guardian spotted a group of students holding signs in English, Japanese, and Korean asking “international friends for help standing up to the Hong Kong government.” They also had some signs made to look like police warning flags advising tourists not to “trust the police or the government.”

The demonstrators also reached out to Chinese arriving in Hong Kong by telling them to head to Yuen Long on Saturday for great discounts on items popular with Chinese visitors. Yuen Long is the location of the train station where last weekend’s mob attack took place. A rally is scheduled to be held there on Saturday despite police refusing to grant the necessary permits, citing the risk of violence. Hong Kong officials on Friday stressed that participating in the Yuen Long demonstration will be considered a violation of the law.

Some travelers and airline employees joined the demonstration, stressing the importance of keeping foreign visitors up to speed on developments in Hong Kong. One flight attendant who participated in the demonstration after getting off work worried too many outsiders think all of the protesters are “rioters or promoting Hong Kong independence,” as mainland China and its supporters in Hong Kong portray them.

The airport demonstration was officially supported by the Cathay Pacific Flight Attendants Union, which encouraged its members to participate and criticized Hong Kong chief executive Carrie Lam for her “incapability” and use of “tricks” to fool the people of the city.

The New York Times also quoted a letter of support from a group of air traffic controllers that Jeremy Tam posted on Facebook. The signatories suggested they might go on strike if the government does not respond to the demands of protesters.

“As we hear the people cry and witness the city descend into chaos, we feel that it is not right to continue to perform our duties silently as if nothing has happened and let the abusers get away with their evil deeds,” said the letter posted by Tam.

Aviation workers staged a sit-in protest in the arrivals hall:

Some travelers, airlines, and foreign agencies expressed concern that the demonstration could paralyze Hong Kong’s only international airport, one of the busiest terminals in the world, but the demonstrators obtained approval from the police. The demonstration was still growing after eight hours, with its numbers swelling into the thousands. According to France24, despite the massive demonstration, there were “no reports of any disruption to flights.”

The Guardian cited a few developments that are likely to make this weekend’s scheduled demonstrations even more vigorous:

In a ruling likely to add to protesters grievances, Hong Kong’s appeal court on Friday overturned the conviction of two police officers previously found guilty of beating a protester in an alley during pro-democracy demonstrations in 2014.

On Friday, Reuters reported that it had obtained a recording from an official from China’s representative office calling on residents in Yuen Long to drive away protesters. “We won’t allow them to come to Yuen Long to cause trouble,” Li Jiyi, the director of the central government liaison’s local district office said at a banquet for villagers in the New Territories, according to Reuters.

Hong Kong executive Carrie Lam is facing a growing rebellion from civil servants who sympathize with the protesters and want allegations of police brutality investigated by an independent commission. Some of Hong Kong’s police unions have urged Lam to oppose the formation of such a commission.

The Hong Kong civil service usually strives to be seen as politically neutral, but the 300 management-level officials who signed a joint statement on Wednesday called on Lam to heed all of the protesters’ demands, including permanent withdrawal of the extradition bill that launched the protest movement and dissolution of the current Beijing-dominated legislature.

Lam essentially disappeared after the Sunday mob attack in Yuen Long, appearing in public only briefly on Monday to denounce the attack while also criticizing acts of vandalism by protesters, an effort at moral equivalence that unsurprisingly infuriated opposition activists.