Azimio leader Raila Odinga has said that Nairobi County's poor planning is the cause of the Embakasi gas explosion.
At least six people have died and more than 280 others were injured following the incident at Mradi area after a gas filling and storage plant caught fire.
Speaking on Monday in Kisumu during the launch of Kisumu Water and Sanitation Company Limited's (KIWASCO) strategic plan, Raila said the gas plant was not supposed to be there.
He faulted the County government saying the tragedy was due to poor planning.
"Currently Nairobi is mourning its dead and treating hundreds of injuries because the city ignored planning and allowed a gas plant where none was supposed to be," Raila said.
The gas explosion that occurred last week on Thursday night at Mradi left a trail of destruction.
On Sunday, Police arrested one of the directors at the National Environmental Management Authority even as they continued to look for more suspects behind the incident.
Nairobi police commander Adamson Bungei confirmed the arrest and declared the hunt for the rest is ongoing.
"Those who are supposed to help in this probe know themselves and are asked to surrender. We are however pursuing them," he said.
He said an autopsy on the bodies is planned as part of the probe into the deaths.
The victims had sustained serious injuries and were admitted to the Kenyatta National Hospital where they succumbed, officials said.
Dozens of other victims have serious burns and are admitted to various hospitals in the city.
Police said they are pursuing at least seven suspects in connection to the incident.
Some of the victims will undergo skin grafting for those with severe wounds.
The process involves transferring cutaneous tissue from one portion of the body to another to cover large wounds.
