Hassan said that medical facilities in the area were overwhelmed.
"Some people have to sleep on the floor, despite their serious injuries. But we are going to airlift the most critical to Nairobi to decongest the hospitals," he said.
In one hospital, severely burned people lay on blankets on the ground, groaning in pain as people searched for relatives.
"I have lost three sons, my fourth and last one was admitted in this hospital with serious injuries. One of those who died was due to join secondary school next week," John Sang said as he stood outside one of the area's hospitals.
"This is a national disaster, it is so unfortunate that we have lost many people in two tragedies in less than a week"
Kenya's interior minister
Supplies, including body bags and extra medicine, were being sent by helicopter to the region.
Raila Odinga, Kenya's prime minister, also suggested that a cigarette had caused the blaze, but said that police were still investigating.
Local residents said there was a suspicion someone angered at being blocked from the spill by police may have started the fire on purpose.
Hundreds of people were crowded around the site after the blaze.
One woman said she was searching for her two missing children.
"My two sons ran home, picked some jerry cans and ran to get some petrol," she said.
"I tried to stop them but they did not listen, they told me everyone is going there for the free fuel."
Al Jazeera's Mohammed Adow, reporting from the capital Nairobi, said that the incident showed the desperation of many people in Kenya.
"It comes at a time when the country is facing an acute shortage of food. The fact that people can risk thier lives by going to try and steal oil from an overturned oil tanker just shows you how desperate the situation is," he said.
The disaster follows the deaths of at least 25 people in Nairobi when a supermarket caught fire earlier this week.
Local newspapers have criticised the government for poor safety regulation.
After the supermarket blaze, the Daily Nation said Nairobi's three million inhabitants are served by just one fire station situated close to a traffic-choked business district.
"This is a national disaster, it is so unfortunate that we have lost many people in two tragedies in less than a week," George Saitoti, the interior minister, said.