A memorial ceremory is held to mark Setp 18, the 82nd anniversary of Japan's invasion of China, in Shenyang, Northeast China's Liaoning province, Sept 18, 2013. [Photo/CFP]

SHENYANG - Air defense sirens sounded on Wednesday morning across China to observe the 82nd anniversary of Japan's invasion.

Sirens began sounding at 9:18 and lasted for three minutes in Shenyang, capital of Northeast China's Liaoning province, where the Japanese army began its assault.

Meanwhile, cars on nine roads, 18 streets and other areas in the city stopped and drivers blew their horns.

It was the 18th time sirens and horns sounded in the city to remind people of the national humiliation as part of routine activities that began in 1995.

People also gathered in front of the "9.18 Historical Museum" to attend a ceremony in which a bell was struck to warn people not to forget the past and be vigilant in times of peace.

Sirens also sounded in 13 other cities in Liaoning province.

In the east China city of Hefei, an air defense drill was organized among local residents after the siren.

On September 18, 1931, Japanese troops blew up a section of the railway under its control near Shenyang, then accused Chinese troops of sabotage as a pretext for the act. They then bombarded the barracks of Chinese troops near Shenyang the same evening, beginning a large-scale armed invasion of northeast China.

The incident was followed by Japan's full-scale invasion of China and the rest of Asia, triggering a 14-year war of resistance against Japanese aggression.