Search and rescue crews are still looking for a 4-year-old girl who went missing on Wednesday at a beach in southeast Shanghai.

The girl's father told news portal Chengdu.cn on Saturday that the search had been extended further down the coast to Zhoushan in Zhejiang province. China Daily was unable to reach him on Sunday for further comment.

According to news reports, Huang Yuanxin went missing while visiting Shanghai Nanhui Beach in Pudong New Area with her family between 5 pm and 6:30 pm on Wednesday.

Her parents contacted police as soon as they discovered her absence. Pudong police immediately conducted a search along the beach, and the local fire administration used infrared search drones to assist. Both groups worked throughout the night but failed to find any clues as to the child's whereabouts.

A 200-member search and rescue team was formed on Thursday, including the experienced Blue Sky Rescue team.

All footage taken by the over 20 surveillance cameras along the beach were checked. According to the footage, a girl resembling Yuanxin was seen walking along the shore and then falling in the water. She appeared to disappear under the waves.

The police confirmed on Friday night that the girl had been swept out to sea.

Huang's father told the police that he had left the girl unattended playing in the sand to fetch his mobile phone.

The details of Yuanxin's disappearance and footage from the surveillance cameras were released by the Pudong police on its official Sina Weibo account on Friday. The police are encouraging anyone with information about the case to come forward.

The incident has attracted many comments online. Among posts of images of Yuanxin before she went missing were heated discussions about the parents' responsibilities and unfounded rumors about the family.

The Pudong police said on Saturday that Huang is Yuanxin's real father and that there is no case in which this has happened to her before, as some netizens speculated.

Li Chenguang, head of the Dandelion Rescue Team Shanghai, told Southern Metropolis Daily on Saturday that they are focusing on the breakwater that runs along the coastline.

"The girl may have been washed back to shore and got stuck under the breakwater," Li said.

The Tenacious Unstoppable Rescue Team in Pudong is also participating in the search efforts after being called up by the Shanghai Emergency Management Bureau on Thursday. Jin Qi, who is leading the team's water search and rescue efforts, agreed with Li that it's possible the girl became trapped beneath the breakwater.

"The golden time span for rescue is 72 hours after an incident. But the time window for a water search is shorter," Jin said.

The search and rescue area has been extended about 10 kilometers upstream and downstream from the site of the incident, Qiu Laiyuan, a member of Blue Sky Rescue told the Shanghai Observer on Saturday.

According to Qiu, the incident occurred in an undeveloped area closed to the public. Though signs have been erected warning of the possible dangers of entering that part of the beach, it has become a hot spot for beachcombers.

Li, from Dandelion Rescue, confirmed that all roads to the area have been blocked off. People can only get onto the beach via a small path in the woods or by climbing over the breakwater, he said.