Thirteen people died in a flash flood that hit Shiyan, northwest Hubei province, at around 4 am on Tuesday, according to the municipal government.

Local meteorological authorities had reported more than 170 millimeters of rainfall between 2:30 am and 5 am in the city's Yunyang district, where the deadly torrent hit, and said the overnight storm was the heaviest in its recorded history.

The city government said a team of about 160 rescuers had been sent out, and displaced people were transferred to a nearby primary school, with a makeshift medical center set up there.

The Ministry of Emergency Management on Tuesday urged the local government to speed up the relief effort, closely monitor potential geological disasters and issue disaster warnings in rain-affected areas in a timely manner.

It was the second deadly flash flood in Hubei since the weekend. A torrent on Sunday killed 13 tourists in Duobi Gorge of Pingshan Mountain, in Hefeng county, in the southwest part of the province.

All victims were confirmed to be unregistered visitors between the ages of 22 and 62 on independent driving tours to the primitive gorge. Five were Hubei natives, four were from Hunan province and the remaining four hailed from Chongqing, county authorities said in a statement on Tuesday.

Among the 61 rescued, five were still hospitalized for light injuries, while the rest were discharged after brief treatment, the statement said.

The county's tourism authorities have been warning travelers not to visit the gorge and other sites in Pingshan Mountain since 2015 because the area remains largely undeveloped. Local travel agencies have been banned from offering tours to such sites.

Adventurers had often referred to the 5,000-meter-long gorge as the Chinese Semporna because the crystal clear creeks between skyrocketing mountains resemble the sea near the Malaysian diving resort.

That has given rise to illegal tours provided by nearby villagers or unlicensed guides. People who had recently visited the gorge said illegal tours were easily available for around 400 yuan ($57) per person.

The county government said last year they criticized and punished up to 500 individuals involved in unlicensed tours to the gorge. Notices had also been sent out via internet and posted at major roads and public places across the county, it said.

Li Shifu, the county's spokesman, said local authorities had repeatedly cracked down on such activities, but the result remained unsatisfactory because visitors could still slip in through numerous hidden routes when law enforcement was off duty.

"It is like a game of cat and mouse," the spokesman was quoted by CCTV as saying.