Harbin, capital of Heilongjiang province, arguably this winter's hottest travel destination, has introduced measures to cater to the growing number of tourists to its solemn war crime museum, just one of the city's many popular attractions.

The Museum of Evidence of War Crimes by Japanese Army Unit 731 in Harbin has witnessed a growing number of visitors since the beginning of this year. To ensure a good experience and a safe and orderly environment, the daily closing time has been extended from 5:30 pm to 7 pm, according to a statement from the museum on Monday.

A new rest area for visitors has been added inside the museum and free bag storage services are also provided, it added.

The statement recommends visitors pick off-peak times and make sure they have valid identification for entry.

According to the museum, since New Year's Day, the number of visitors to the museum has exceeded 200,000.

The 10,000-square-meter museum is divided into six exhibition areas. It is devoted to examining the secret biological and chemical warfare research base established by Japan in Harbin in 1936 that served as the center of its biological warfare efforts in China and Southeast Asia.

Unit 731 conducted experiments on people to test germ-releasing bombs and chemical weapons, among other atrocities during the War of Resistance Against Japanese Aggression (1931-45).

At least 3,000 people were used in human experiments by Unit 731, and more than 300,000 people across China were killed by Japan's biological weapons.

After more than 30 years of investigation and collection, the museum now has nearly 100,000 relics and historical materials in seven categories, according to the museum.

Despite waiting for nearly two hours in the extremely cold weather before entering the museum, Qi Liangliang said she would never regret making the visit during her two-day trip in Harbin.

"Before this visit, I only knew some information about the atrocities of Unit 731 from history books and some film and television works," said the 29-year-old tourist from Shanghai. "Although I was fully prepared before entering, I was still shocked during the visit.

"I want to say thank you to Harbin for your efforts to preserve and restore history," said Qi.

"Every word and photo in the museum are witnesses of human suffering and a special memory left by the cruel war, making me feel the responsibility of remembering history."

Several local residents have picked up on the surge in tourism and decided to show their volunteering spirit by offering free services. One such resident, surnamed Zhao, hired four minibuses to provide free transportation to the museum, which is around 25 kilometers from the city center.

"I was quite moved to see that many tourists visit the museum during their trip in Harbin," he told Beijing Youth Daily. "When I found some tourists wanting to go there with their luggage, I decided to do something for them."

"I will keep the buses for at least the next two weeks and adjust according to the needs of tourists."