Voting in the Ol Kalou parliamentary by-election was thrown into turmoil on Thursday after masked, armed men descended on crowds gathered outside polling stations, triggering violent confrontations that left voters fleeing, journalists assaulted and cameras confiscated as the exercise entered its final hours.
The violence unfolded at a time of heightened political tension and followed claims by former Deputy President Rigathi Gachagua that there were plans to interfere with the election.
Some of the worst scenes were witnessed at Ol Kalou Comprehensive School and AC Primary School, where hooded men travelling in unmarked vehicles confronted groups of youths and attempted to drive away voters and members of the public gathered outside the polling stations.
Witnesses said teargas canisters were fired from vehicles accompanying the group, causing panic as voters and residents scattered from the polling centres.
Members of the media covering the by-election were also caught up in the violence, with journalists reportedly assaulted and their cameras confiscated during the confrontations.
Videos shared online appeared to show masked men carrying firearms and batons moving through crowds outside polling stations. Other clips showed people running in different directions as the armed group attempted to disperse voters and onlookers.
Witnesses also said a police Land Cruiser carrying security officers forced its way through crowds outside Ol Kalou Comprehensive School after voters remained at the polling station, insisting they wanted to safeguard the electoral process.
The unrest came hours after Gachagua accused politicians allied to the ruling United Democratic Alliance (UDA) of working with rogue police officers to interfere with the election.
"Having sensed defeat, UDA-allied MPs are allegedly meeting with rogue police officers to storm major polling stations, disrupt voting, and stuff ballot boxes," Gachagua said.
He also accused the Inspector General of Police of failing to act on concerns over the deployment of plain-clothes officers.
"Bwana IG, I told you that rogue police officers in plain clothes are your weakest link. They are the source of insecurity in the country. If you are not part of this scheme, you have a duty to order the uniformed police officers to stop them. If you do not, then you are part of the scheme and must take responsibility for any violence that may occur." Gachagua stated.
The DCP leader further urged election observers, journalists and members of the public to closely monitor polling stations at Huruma, St Joseph and AC Primary School, saying any attempt to disrupt the election should be documented.
Earlier in the day, Central Regional Commissioner Joshua Nkanatha warned that vehicles operating without registration number plates would be impounded as security agencies tightened surveillance during the by-election.
He said driving a vehicle without registration number plates is an offence and warned that any such vehicle found by police officers would be seized and taken to the nearest police station.
Nkanatha also cautioned unauthorised individuals against lingering around polling stations, saying only IEBC officials and registered voters should be allowed within polling centres, while everyone else must remain at least 400 metres away.
The Ol Kalou parliamentary by-election was called following the death of longtime Jubilee Party MP David Njuguna Kiaraho, who died on March 29, 2026, after representing the constituency for more than a decade.
The contest has drawn national attention as a key political showdown between UDA and Gachagua's Democracy for the Citizens Party (DCP), with the outcome expected to influence the political direction of the Mt Kenya region ahead of the 2027 General Election.