At least six people were killed as relentless rainfall battered Karachi on Monday, submerging several areas of the city and leaving many without power on the second day of Eidul Azha.

According to the police, five men were killed by electrocution in various areas while one died due to a wall collapse. Further investigation was under way, Karachi Police said.

Despite the Sindh government's claims of cleaning out the city's storm drains, overnight showers caused rainwater to accumulate on roads and in neighbourhoods in scenes reminiscent of the disastrous torrential downpour witnessed in August 2020.

Citizens on social media complained of prolonged power outages and roads turning into "rivers" as #Karachirain trended on Twitter.

However, Karachi Administrator Murtaza Wahab said the "quantum of rain has been 126mm in certain areas of Karachi in three hours".

He said that the nullahs and drains were taking water, but the process was slow. "The pumping stations are also working at a packed capacity. We are trying our best to address the situation. CM & his team are in the field," he added.

According to data released by the Pakistan Meteorological Department (PMD), PAF Masroor Base received the highest amount of rainfall (119.5mm) in the past 24 hours followed by DHA Phase 2 (106.6mm), Quaidabad (76mm), PAF Faisal Base (65mm), Orangi Town (56.2mm), old airport area (49.8mm), Gulshan-i-Hadeed (46.5mm), Nazimabad (31.8mm), Jinnah Terminal (29.6mm), University Road (14.8mm), Surjani Town (14.4mm), Gadap Town (9.2mm), North Karachi (2.3mm) and Saadi Town (1.1mm).

Later, Wahab tweeted that the Frere nullah was "flowing well".

Separately, the traffic police said that the Submarine Chowk underpass, KPT underpass, and the one near the shrine of Abdullah Shah Ghazi were closed due to the accumulation of rainwater.

Several areas remained water-logged well into the afternoon after the rain stopped. Sindh Secretariat's Kabootar Chowk was among the areas flooded.

Chief Minister Shah directed all relevant departments to expedite work to address the rain emergency. After a visit to several water-logged areas along with Karachi Administrator Murtaza Wahab and other officials, he issued instructions to immediately drain the road leading to Jinnah Hospital from Taj Mahal Hotel so vehicles shouldn't face problems reaching the hospital.

He also issued orders to deploy suction pumps across the city to speed up the drainage of water.

He also called a meeting at the Chief Minister House to discuss the situation.

Prime Minister Shehbaz Sharif said he was "deeply saddened" by the damage wrought by the torrential rains and that he had had spoken to Sindh Chief Minister Murad Ali Shah.

"I am confident that Sindh government will rise to the occasion and bring life back to normal under the able leadership of CM Sindh. Have offered to extend every possible support."

CM says high tide made drainage difficult, praises Wahab for 'unprecedented' service

In a media briefing, Chief Minister Murad Ali Shah said there was a severe spell of rain in various areas of District South, about 232mm — nine inches — within 15 hours. He highlighted the challenges that authorities faced when attempting to clear the flooded roads.

He said as soon as the rain let up, resources already deployed to various localities were put to work.

He also cited the challenges of high tide, which he attributed to a forthcoming full moon, which slows down drainage into the sea.

He said he had himself seen the nullahs, which were "absolutely full to the brim" and flowing beyond their capacity.

"We have deployed our machinery and our ministers are on the roads. I myself spent 2.5 hours touring the city," Shah said.

He said from the CM House, he went to Sharea Faisal, turned on to Karsaz, and from there, he went towards Jail roundabout. He also said he went to the centre of the city, particularly the area around Sindh Secretariat, which he described as being submerged.

The area around the High Court, and the Supreme Court registry was also water-logged.

"We will try our best to [clear the roads] as soon as possible," Shah said.

He warned that the rains were likely to continue. He said there was rain forecast for today, which would ease by tomorrow, however, it would gain pace by Wednesday.

"It's very important for us to clear the roads of water [before the rain intensifies]," Shah added.

The chief minister said at this moment, the worst-affected areas were District South localities, which include Defence, other cantonment areas, Lyari and Saddar.

He said all the ministers have been deputed in their designated areas, and singled out Karachi Administrator Murtaza Wahab for praise. "I do not think this level of work had ever been done in Karachi before."

Shah said he has instructed the city administration to provide shelter to the residents of low-lying areas where water has breached residential premises.

He blamed illegal constructions over nullahs and natural waterways — including government's own installations — for the flooding, acknowledging that perhaps the provincial authority will have to take the lead in tearing down such buildings.

'Don't leave home unnecessarily'

Commissioner Karachi Muhammad Iqbal Memon urged Karachiites to not leave their homes unnecessarily and stay away from electricity poles. "Stay away from utility lines poles, wires and nullahs."

In a statement, he also cautioned people to keep their distance from drains and manholes.

Taking to Twitter, he shared emergency contact details.

Heavy rain predicted

Meanwhile, the Met department predicted heavy rainfall and thunderstorms in Karachi, Thatta, Badin and Hyderabad.

Chief meteorologist Sardar Sarfaraz said the new weather system headed towards the city would last until July 18-19.

Sarfaraz also said that intermittent rain with thunder was also expected in Mirpurkhas, Umerkot and Tando Mohammad Khan. He also warned of a risk of flooding in low-lying areas in Karachi, Badin, Thatta, Mirpurkhas and Umerkot.

In an update shared on Twitter around 2:30am, the K-Electric spokesperson claimed that the power supply system within its territory was stable.

"Most areas of the city continue to receive power from more than 1,770 feeders out of 1,900," he said. He added that around 130 feeders were closed as a precautionary measure due to reports of power theft or accumulation of rainwater.

The week-long monsoon spell has already claimed the lives of several citizens. Six people were killed in rain-related incidents on Friday while seven were electrocuted to death on Saturday.