Two people - a man and woman - have been arrested over allegedly voter bribery at a polling station in Kibra.
This is according to Nairobi Area police boss Philip Ndolo, who said the two are in police custody as investigations into the matter continues.
The security agencies overseeing the exercise were alarmed by a fracas which prompted them to arrest the two.
The police boss also noted the security has been beefed up in the constituency to prevent a re-occurrence of such incidents.
Earlier on, commotion was witnessed at Lindi Polling Centre where a group of youths, led by Suna East MP Junet Mohamed, chased away a number of local leaders whom they accused of bribing voters at the centre.
In a video that is making rounds on social media former Kakamega Senator Boni Khalwale is seen hurriedly walking out of a location that appears to be in Kibra.
Nairobi News has learnt that voters started arriving at the all the 183 polling stations in the constituency from as early as 5am to cast their votes.
Some 26,788 voters registered in 36 polling stations were relocated to new voting areas as their registered polling stations are engaged with ongoing examinations.
Kenya Integrated Election Management System kits (KIEMS) failed in some polling stations but Independent Electoral and Boundaries Commission said the malfunction kits have been replaced.
6am - The polling stations across the constituency were opened at 6am to a smooth start of voting. A spot check across the stations shows queues building up.
8am - Commotion ensues at a polling station in Mashimoni Squatters after voters rough up a man they accuse of trying to bribe them with Sh200.
8:50am - Monica Okoth, widow of former Kibra MP Ken Okoth, casts her vote at the Old Kibera Primary School.
10am - Police arrest Langata CDF committee member James Kipkorir for allegedly engaging in voter bribery at Mashimoni, Kibra Constituency.
10:32am - ANC candidate, Eliud Owalo, votes at Old Kibra Primary School. He is accompanied by ANC party boss Musalia Mudavadi and other officials.
11am - Orange Democratic Movement (ODM) candidate Bernard Okoth casts his vote at Old Kibra Primary School.
11:30am - ODM party leader Raila Odinga votes at Old Kibra Primary School accompanied by his wife Ida and daughter Winnie.