Lax safety measures and a shortage of police officers may have contributed to the fatal New Year’s Eve stampede in Shanghai which killed 36 people and left scores injured.

There were 5,000 fewer officers on duty on Wednesday night than on New Year’s Eve the previous year, according to Associated Press. Traffic controls implemented the previous year were also abandoned because the official light show had been cancelled.

Before the 2013 celebrations, Shanghai authorities deployed 6,000 police officers and requested help from military police to manage the 300,000-strong crowd. Just 700 officers were on duty this year.

According to state media, last year police closed off access to an elevated viewing platform and to the nearest subway station in an attempt to control the crowd. But last week, despite the same number of revellers showing up to welcome in the new year, the subway station remained open and people were free to climb the staircases to the platform.

Shanghai had hosted a New Year light show on the Bund riverfront for the previous three years, but authorities cancelled it this year because of concerns about overcrowding. Instead, a smaller light show was held at a nearby 2,000-person venue that required admission tickets.

But hundreds of thousands of people still turned up for the traditional show on the riverfront. When the authorities became alarmed by the size of the crowd, they drafted in another 500 police officers, but by then it was too late to prevent one of the biggest disasters to strike a Chinese city in years.

Three dozen people ended up asphyxiated or trampled to death in a stampede at the bottom of a 17-step, 5-metre-wide concrete staircase which led to one of the best vantage points to view the Huangpu River. Nearly 50 others were injured.

Witnesses said people were trying to climb the staircase to the viewing platform as others tried to get down, causing panic and confusion. Investigations are continuing into how the tragedy occurred.

“You cancelled the light show, but did you properly notify the public?” asked a father who lost his daughter in the stampede, according to AP. “Once people started to show up in the hundreds of thousands, did you have backup measures to ensure safety? What were you doing during the time the crowds were growing? The government has been seriously derelict of its duties,” he said.

Zhao Chu, a local resident, said: “It’s been a tradition to see the lights on the Bund on New Year’s Eve. Shanghai people know it, and the whole country knows it.

“The government should have foreseen the crowds on that night. Such incidents could have been avoided.”

Patrol officer Wang Qiang told state media: “Because there was no scheduled event, there was no traffic control,” adding that tourists kept asking him if there would be a light show.

As midnight approached, authorities reminded revellers that the show had been cancelled, and the stampede began at around 11.35pm.