Air raid sirens echoed through the city of Shenyang, Liaoning province, at 9:18 am on Sunday to remember the outbreak of the War of Resistance Against Japanese Aggression 91 years ago.

More than 300 people from all walks of life, including veterans, students and local residents, participated in the commemoration in front of the square of Shenyang 9.18 Historical Museum.

The bell rang 14 times, representing the 14 years during which the Chinese people fought the invaders. The period has been referred as the darkest days of modern China.

Shenyang, along with other 13 cities in Liaoning province, sounded the air defense alarm for three minutes. Motor vehicles, ships and trains all sounded sirens at the same time.

"The alarm of bell and siren is to salute the brave struggle of that year and warn ourselves to remember the history. We bear the future of our motherland, and should cherish the peaceful life," said Wang Qiming, a local high school student.

On Sept 18, 1931, members of the Japanese Kwantung Army stationed in northeastern China blew up a section of the railway near Liutiaohu and falsely accused the Chinese military of doing it. Using the incident as a pretext, the Japanese bombarded Shenyang and launched its invasion of China.

"The landmark construction of our museum is called the calendar monument. The shape of the monument is a calendar broken by shells and bullets. The bullets holes on the tablet form the image of skulls, which indicates Chinese people were killed in those dark years," said Han Xiao, a commentator of "September 18" History Museum.

Behind the museum, there is an railway linking Harbin with Dalian. It was part of the South Manchuria Railway, where the incident occurred 91 years ago.

The museum was built in 1991 to mark the 60th anniversary of the 918 Incident. At present, it houses more than 1,000 precious historical photos and more than 3,000 sets of historical relics.

Since 1995, Shenyang has been sounding an air defense alarm every year on this date.