A section of Mombasa's NASA supporters made good their threat to demonstrate despite a ban by acting Interior CS Fred Matiang'i.
A crowd took to the streets on Friday to show support for Opposition leader Raila Odinga who is in the UK.
MPs Abdulswamad Nassir (Mvita), Badi Twalib (Jomvu), Senator Mohamed Faki and several MCAs were among politicians who took part.
Before the march began, Nassir reiterated police have no authority to disperse legal protests.
The supporters and their leaders called for the removal of IEBC chief executive Ezra Chiloba.
They marched along Moi Avenue while displaying the two-finger peace sign. Police tried to block them but they carried on.
Hell broke loose when they were about a kilometer from IEBC offices situated next to State House Mombasa.
Police following Matiang'i's order hurled at least 20 teargas canisters to break the demonstrations.
They clobbered some of the supporters while others scampered for safety.
The NASA chief and other Opposition leaders called the protests to push for reforms at the electoral agency. Their slogan - 'no reforms no elections' - concerns claims the August 8 vote was rigged in favour of President Uhuru Kenyatta.
Raila and his running mate Kalonzo Musyoka (Wiper) have withdrawn from the election in a demand for a fresh process.
"TEARGAS NOT SOLUTION"
Matiang'i issued the ban after Opposition leaders said their mass action would intensify. They also don't want amendments to election laws with just days to the election.
Nassir said yesterday that they would take to the streets despite Matiang'i's order. Today, he had Faki condemned police action saying it was uncalled for.
"We want to tell this government that tear gas is not the solution. We are demonstrating because we are agitated by the current political dictatorship we are being subjected to, so Matiang'i should not try to limit us from expressing our concerns," said the Mvita legislator.
Nassir noted all NASA principals are expected to attend Sunday's demonstration, which is expected to be the "mother" of them all.
The other principals are Musalia Mudavadi of Amani National Congress and Bungoma Senator Moses Wetang'ula who is Ford Kenya boss.
Faki said it is unreasonable for police to lob tear gas at them yet their protests have always been peaceful.
"Five times we have held demonstrations here. We have been peaceful...no one has complained that we have destroyed their property. Why should they then attack peaceful protesters?"
After Matiang'i banned protests in the CBDs of Nairobi, Kisumu and Mombasa, Nassir said they would still take to the streets.
The second-term legislator noted the Cabinet Secretary does not have the right legitimise a protest.
Matiang'i noted there has been mass destruction of property. Singling out NASA CEO Norman Magaya, he said organisers will be held personally liable if orders are broken.