The public security bureau in Harbin, Heilongjiang province, issued a wanted notice on Wednesday for a female suspect in connection with a hotel fire that killed 20 people on Saturday.
Police offered a reward of up to 300,000 yuan (S$60,000) for information that assists in finding Li Yanbin, 52, a native of Harbin.
It provided no details about her alleged connection with the fire.
Meanwhile, Beijing Jiufangyuyue Commercial and Trading Co confirmed the identities of the 20 people killed in the blaze.
"All the victims were members of a tour group we organised, consisting of three staff members and 88 seniors," Zhao Chunlan, the legal representative of the company, was quoted as saying in China Newsweek. "The 12 female and eight male victims are all Beijing residents, age 59 to 85."
The 10-day trip, starting from Beijing on Aug 16, should have concluded on Saturday in Harbin, the final destination. The tourists spent the first five days in Daqing and Wudalianchi and arrived in Harbin on Aug 21.
The blaze at the four-story Beilong Hot Spring Hotel started at 4:36 am and was extinguished by 7:50 am, after firefighters evacuated more than 80 people and rescued 20 others who had been trapped.
The firefighters found 19 bodies.
24 people who were injured, including firefighters, were sent to the hospital. One of those injured died while undergoing treatment.
The tour company's business scope included food marketing, healthcare products, household electrical appliances, clothing, shoes, hats and fresh fruits and vegetables on top of its tourism consultation－a feature added in August 2017－according to the website of the Beijing Administration for Industry and Commerce.
"The customers are awarded tour days when they buy the recharge card for our commodities－60 days for a 19,000-yuan ($2,800) card, and 90 days for 29,000-yuan card," Zhao said. "We will also design tour routes on demand for customers."
"We have become a franchisee of Beijing Lantianzhilv International Travel Agency," she added, although Duan Zhenhai, the legal representative of Beijing Lantianzhilv said there was no such relationship.
"The group lived in a hotel in the centre of the city for the first several days and moved to the hot springs hotel in Songbei district for the final night," Zhao said. "They enjoyed a bath in the hot spring after visiting an indoor ice and snow park near the hotel."
According to the provincial fire department's website, the hotel, which opened in 2015, had failed to pass four fire safety inspections since December.
There were several fire risks in the hotel, including a lack of fire extinguishers and malfunctioning indicator lights for emergency exits. Two exits had been locked, local media reported.
"I didn't hear any smoke alarm until after the fire was extinguished, and I couldn't find a fire hydrant in the building," a staff member of the tour group said. "There was heavy smoke in the corridor and no indicator lights pointing to the exit."
Police have detained the legal representative of the hotel, Zhang Weiping, 46. Officials are also looking into the cause of the fire.