SHANGHAI, Jan. 7 -- Shanghai's top official on Wednesday said he felt deep grief and guilt over the New Year's Eve stampede that left 36 people dead and 49 injured.

Addressing a government conference on strengthening safety management, Han Zheng, Secretary of the Communist Party of China (CPC) Shanghai Municipal Committee, lamented the huge loss of lives and ordered officials to learn a lesson from the tragedy.

Han said an investigation is under way and officials will be held responsible.

The officials should acknowledge the flaws in their work and draw a lesson to improve their work, Han said. He added that they should try their best to ensure the safety of life and property of each city resident.

He said authorities will launch a thorough overhaul of the current safety management system and take more stringent measures to guarantee city-wide safety.

Shanghai Mayor Yang Xiong said the joint investigation should be objective, fair and authoritative and related information should be released in a timely and transparent manner to address the public's concerns.

Yang ordered improved safety management for large crowds in key places, such as stations, airports, scenic spots and shopping malls, and demanded precautions to brace for emergencies.

The deadly stampede happened when people assembled on Shanghai's historic riverfront walk, the Bund, to usher in the new year last Wednesday night.

According to the Shanghai Municipal Health and Family Planning Commission, 17 injured people were still receiving medical treatment as of 11 a.m. on Wednesday.

Among them, four were seriously injured and one was in critical condition, the commission said.

To mark the seventh day after the tragedy, citizens and victims' families visited the site of the stampede on Tuesday.