Many Kenyans have ignored opposition leader Raila Odinga's call for a strike over disputed elections.
In the capital Nairobi and other cities, many shops remain open.
At least 24 people have been killed in violence since the 8 August election, the Kenya National Commission on Human Rights has said.
Mr Odinga said the poll was rigged to give President Uhuru Kenyatta victory, and called for a "day of mourning for the fallen patriots".
However, Kenyans on Twitter have been using the hashtag #TurudiKaziniChallenge (Swahili for "Let's return to work" ) to urge a return to normalcy following last week's disruptions.
Mr Kenyatta repeated his appeal for peace.
"At the end of the day we are all Kenyans, we don't need to fight one another, we don't need to destroy each other's property, we don't need to take life," he said in a statement.
"Kenyans have said that the election is behind them, the majority have returned to work," he added.
Young people have been burning tyres in Kibera, a Nairobi slum where Mr Odinga has strong support, reports the BBC's Tomi Oladipo from the scene.
However, some of Mr Odinga's supporters in Kibera have opened their shops, saying that while they agree with him that the result was rigged, they cannot afford to lose business, our reporter adds.
Businesses are open as usual in the coastal city of Mombasa.
In the western city of Kisumu, a stronghold of Mr Odinga, there has been a mixed response to the strike, with shops open in some areas and shut in others.
The official results gave President Kenyatta about 54% of the vote, and Mr Odinga 45%.
"This is a failed regime that is resorting to killing people instead of addressing the real issue. The vote was stolen. There's no secret about that," Mr Odinga told his supporters on Sunday, as he called for a strike.
Foreign observers have declared the poll free and fair.
European Union foreign affairs chief Federica Mogherini and former UN Secretary General Kofi Annan are among those who have urged Mr Odinga to seek redress through the courts - something the opposition coalition says is not an option.