A siren wailed for three minutes to mark the Sept 18 Incident, also known as "Mukden Incident".

This was the first time the three provinces had held such a memorial together. More than 1,000 people gathered at the square of the "918 Museum" in Shenyang to watch the ceremony.

Four selected representatives stroked the bell with Wang Min, Party secretary of Liaoning, and other governors. They beat it 14 times, which indicated the 14 years of resistance in northeastern China.

"We should always sound the alarm and make the incident a marker of our country's development and revival," Wang Min said at the ceremony.

Zhao Yixian was one of the four people chosen to ring the bell.

"It's my honor to be selected as a bell ringer," he said. "Maybe I'm the first Taiwan resident chosen to do this, which will encourage Taiwan people to remember this part of history."

Local resident Qiu Baoming, 75, who lives near the museum, has participated in annual ceremonies at Shenyang for nearly 20 times.

"I got here at 6 am," Qiu said. "This year's ceremony was so solemn.

"Our country is stronger and people's lives are happier now. I think we can replace evil with good, but we should remember history, so that sort of thing will never happen again."

On the roads in the city, cars also drew to a halt and honked their horns to remember a black day in the country's history.

On Sept 18, 1931, Japanese troops destroyed a section of railway in northern Shenyang and attacked the Chinese garrison in the Beidaying area of the city that same night.

The events were followed by Japan's total occupation of China's northeast regions. As many as 35 million Chinese were killed or wounded by invading Japanese troops between 1931 and 1945.

To remind people not to forget the humiliation, since 1995 Shenyang authorities have encouraged their citizens to ring the ceremonial bell and honk their horns every Sept 18.

This year the government changed the alarm time from 9:18 pm to 9:18 am to make it more convenient for citizens to take part in the ceremony.

Nationwide, sirens wailed in more than 100 cities around the country on Sunday to observe the 80th anniversary of Japan's invasion of China.

In Beijing on Sunday, an exhibition depicting the Japanese aggression against China was held in the Museum of the War of Chinese People's Resistance Against Japanese Aggression.

More than 600 historical relics and 133 photos, most of which are on display in China for the first time, will be on show until March 31, 2012.

The Japanese invaders took most of the photos at the exhibition, some of which had been prohibited from being shown in public by the Japanese government in an attempt to cover up the criminal acts.

A banner by a Japanese veteran of the invasion apologizing for his crime is also on show at the exhibition, which was jointly mounted by the memorial hall, the Society for the History of China's Anti-Japanese War, the Institute of Modern History of the Chinese Academy of Social Sciences and the Beijing Society of Anti-Japanese War Research.