Kenya's Deputy President William Ruto has disowned food donation said to be contaminated that was distributed in a constituency outside the capital, Nairobi, in bags branded with the name of his foundation.

Scores of people have visited hospitals after consuming the food, with some patients in critical condition - according to Kiambu County Governor James Nyoro.

Mr Ruto on Monday denied involvement in the distribution of the food, blaming it on "political thuggery".

"Reports from locals indicate that the strange food donations in question were hurriedly thrown from moving vehicles to unsuspecting public with fake branding, that is not from the Foundation," a statement from his spokesperson said.

Some residents are reported to have returned the foodstuffs to local administrators, according to media reports. Each bag carried a packet of maize flour, cooking oil, tea leaves among other essentials.

Kenyan politicians have been distributing foodstuffs in low-income areas where people's earnings have been hard-hit by coronavirus containment measures.

The government has restricted movement in and out of Nairobi and the second biggest city of Mombasa, as well as two other counties in the coastal region. It has also imposed a night to dawn curfew.