Police were on Friday morning forced to lob teargas to disperse a section of National Super Alliance (NASA) supporters who had started marching towards the Jomo Kenyatta International Airport (JKIA).
The supporters reportedly blocked roads and lit bonfires making it difficult for vehicles to use Mombasa Highway.
Police moved in and dispersed the crowd from the roads.
Reports indicate that so far, four roadblocks have been set up between Airtel building on Mombasa road and JKIA.
There is also a heavy police presence both on the highway and at the airport entrance.
The Opposition supporters have also gathered in large numbers in readiness for the one million people's march to welcome Opposition leader Raila Odinga.
A police officer was injured in the altercation with the Opposition supporters after he was hit with a stone on the head.
The running battles between the police and the Opposition supporters has created a huge traffic jam along Mombasa road as motorists as subjected to thorough checking on the various roadblocks along the highway.
The same situation was replicated in Jogoo road where supporters of Mr Odinga burned tires blocking motorists from accessing the road.
Mr Odinga is expected to jet back to the country today after a 10-day tour of the United States and Europe.