The police chief has said the protests are a threat to national security and has deployed riot officers across the country.

In some towns, including Nairobi and Nakuru in the Rift Valley, protesters have barricaded roads and been hurling stones at police.

There are reports of several people being injured in such confrontations in Migori, a county in the west of the country.

Christine Wema, the director of Migori's Oruba nursing home, told the BBC that two men had been brought into the facility with leg injuries, probably caused by rubber bullets used by the police

Another person had been admitted with breathing problems after a tear-gas canister was lobbed in his house, she said.

Rights groups and diplomats have expressed deep concerns about the situation in Kenya, urging the government and opposition to resolve their differences peacefully.

The two sides had agreed to hold talks earlier in the year, but the opposition said Mr Ruto's team was not committed to resolving their complaints.

These include the soaring cost of living as well as the conduct of the elections last year, narrowly won by President Ruto, who promised to champion the interests of the poor.

However, since taking office, he has done little to tackle inflation and his government has raised taxes - doubling the VAT on fuel.

Tensions are likely to be fuelled further by reports in the local media that the security details for opposition leaders Raila Odinga and Kalonzo Musyoka were removed ahead of this week's protests.

Security officers assigned to Ngina Kenyatta, widow of Kenya's first president, have also been reportedly withdrawn. She is also the mother of ex-President Uhuru Kenyatta, who is an ally of Mr Odinga and who has been accused by th government of funding the protests.