Police have arrested Steve Mbogo, Ruaraka MP TJ Kajwang and Embakasi East MP Babu Owino as they made their way to Kamkunji Grounds in Kibera for National Super Alliance (NASA) rally on Thursday.
NASA had planned to hold what it termed a "grand rehearsal" at the Kamkunji grounds this Thursday.
The NASA leaders have been taken to Kilimani Police Station.
The rally was dress-rehearsal for the Friday grand welcome of NASA leaders Raila Odinga and Kalonzo Musyoka.
The organisers said the Opposition leaders will be received at Jomo Kenyatta International Airport on Friday from where they will begin a procession on Mombasa Road before concluding with a rally at Uhuru Park.
On Wednesday, the National Police Sevice Spokesman George Kinoti warned that the National Super Alliance (NASA) plan for Raila Odinga’s grand reception would ompromise airport security.
Mr Kinoti said the march by NASA supporters would not only be a security risk but the organisers would also be noncompliant with the Public Order Act (2016).
The police spokesman noted that JKIA is a protected area and only people with valid reasons could be allowed access to the premises.
NASA leader Raila Odinga and Kalonzo Musyoka are expected to depart Germany on Thursday night and arrive in Nairobi Friday morning in time for a series of political rallies in the city.