A gas leak in the Pakistani port city of Karachi has killed 14 people and left hundreds more ill, health officials said.

The leak set off a panic in the city and raised concerns because city officials could not immediately identify the source and type of gas involved. Officials said there was no suspicion of sabotage.

The apparently odourless gas, which causes severe breathing problems, has made hundreds sick since striking the coastal neighbourhood of Kamari on Sunday night when residents began going to local hospitals.

Pakistan Toxic Leak
People pray for a victim of the toxic gas leak at his funeral in Karachi (Fareed Khan/AP)

Zafar Mahdi, a senior health official, put the death toll at 14 on Tuesday.

Authorities said they were planning to evacuate residents from Kamari to safer places by Tuesday evening. Scientists and chemical experts from the army and navy were deployed to the area to detect the source of the leak.

Syed Murad Ali Shah, chief minister in Sindh province, acknowledged that authorities were still unable to determine what caused the toxic gas leak, which he said had not spread to other parts of the city.

Hundreds of residents rallied on Tuesday demanding the source of the leak be traced quickly.

All of the stricken people — hospitals said they had treated more than 650 — were residents of Kamari.

Pakistan Toxic Leak
Sher Bahadur, a victim of the toxic gas leak, talks to media outside hospital (Fareed Khan/AP)

One patient, Babar Bahadur, said on Monday he first felt an ache in his eyes and a pain in his chest.

“My heart started beating suddenly very, very fast,” he told the Associated Press. He said he was rushed to hospital where he was treated and felt better “after quite some time”.

He said his son experienced some of the same symptoms and was also briefly treated at the hospital.

Port officials insisted no gas leaks occurred at any of their facilities.

Karachi is the capital of southern Sindh province, Pakistan’s largest city and the country’s chief commercial hub. It has oil refineries nearby and a key installation of Pakistan’s navy.