How did the anti-Japanese regiment bomb the cinema bought by the Japanese in Tianjin?

At that time, two cinemas "Guanglu" and "Guotai" in Tianjin were bought by the Japanese, and the resistance group decided to set fire to them. Sun Ruoyu and others made two incendiary bombs, and the operators were divided into two groups. Before departure, Shen Dong announced that before the break (at that time, the film had a 10 minute break in the middle of the screening, and the audience didn't take their seats accordingly), he put the timed incendiary bomb under the screen to make it catch fire after 20 minutes. Once it was placed successfully, he covered the lantern with a red cloth to signal. When the players sitting in the first row upstairs saw the signal, they dropped anti-Japanese leaflets signed by anti-Japanese groups and then retreated. Shen Dong also prepared a bomb in a can, weighing about two kilograms. In case of an accident when he placed the incendiary bomb, use the dry battery to detonate the bomb to disturb the order and facilitate evacuation. Later, because things went very smoothly, everyone retreated safely and the bomb was not used. According to Lu Naipu, a female member who stayed to see the effect, when the incendiary bomb exploded, only a piece of white light was seen, the screen was burned, and the audience panicked and rushed to escape from the theater. When she ran into the street, the fire was still spreading, and soon the building caught fire. With a loud noise, the building was destroyed and the whole theater suddenly became a pile of ruins. This was the first big action of the anti-Japanese gang, which caused great panic among the enemy and puppet troops.