Kenyan police have tear-gassed opposition leader Raila Odinga's convoy in the capital, Nairobi, as he spearheaded the biggest protest against President William Ruto's government since it took office.

The protests have also spread to other cities, with a university student reportedly shot dead in Kisumu.

Odinga accuses the government of being "illegitimate", and of failing to tackle the high cost of living.

President Ruto has rejected the claims.