The father of a three-year-old boy who died from carbon monoxide poisoning in north-west China said strict Covid-19 policies “indirectly killed” his son by causing delays obtaining treatment.

The boy’s death on Tuesday sparked outrage on social media and is the latest incident to trigger blowback against China’s strict zero-Covid policy.

“I personally think that he was indirectly killed,” the boy’s father, Tuo Shilei, told Reuters by phone from the city of Lanzhou, which has been under lockdown for several weeks.

Tuo noticed that his son, Wenxuan, was unwell after his wife slipped and fell after being affected by gas fumes while cooking on Tuesday. Tuo said he tried desperately to call for an ambulance or police, but could not get through.

After about 30 minutes Wenxuan’s condition worsened, and Tuo said he performed CPR, which helped briefly. He rushed with his son to the entrance of their community compound, which was under strict lockdown. Staff at the gate would not let him past, telling him to call neighbourhood authorities or an ambulance.

Frantic and unwilling to wait any longer for an ambulance, Tuo crashed through the barriers with his son and locals called a taxi to take them to a hospital, where doctors’ efforts to save Wenxuan were unsuccessful.

“There was the Covid situation at the checkpoint. The staff did not act, and then ignored and avoided the problem, and then we were blocked by another checkpoint,” said Tuo.

“No help was provided. This series of events caused the death of my child.“

The Lanzhou government and department of health, as well as the Gansu provincial government, did not immediately respond to requests for comment.

During last month’s Communist party congress, President Xi Jinping reaffirmed China’s commitment to the zero-Covid policy that has made it a global outlier and led to disruptive lockdowns in cities across the country.

Wenxuan’s story began trending on social media after a video was shared of him receiving CPR while on the back of a truck, along with a comment suggesting he died due to delays getting treatment.

One hashtag, “Three years of Covid was his entire life”, became a trending topic before it was scrubbed, a common occurrence on China’s heavily censored internet.

“The kid’s memory will sadly be of masks and nothing else,” one Weibo user wrote.

“Is there any trust left in the authorities?” wrote another user.

A number of cases of people dying because they were unable to get medical care due to Covid restrictions have drawn viral outrage this year, including many during Shanghai’s two-month lockdown.

Tuo said he was later contacted by a person who said they were a retired local official and offered to arrange for him to be sent 100,000 yuan ($13,000) if he signed a pledge agreeing not to go public or seek redress over the incident.

Tuo said he rejected the offer and instead demanded an explanation for his son’s death.

On Wednesday morning, a funeral for Wenxuan was held in the family’s nearby home town of Hezheng. Tuo did not attend, for fear of being quarantined on arrival.