Chaos, teargas, running battles and suspected live bullets marred opposition leader Raila Odinga's entry into the capital Nairobi's city centre upon his arrival from the United States on Friday.
Mr Odinga and his daughter Winnie landed at the Jomo Kenyatta International Airport (JKIA) in Nairobi at 11.13am (+3 GMT), after a 10-day trip in the US.
From morning, traffic on Mombasa Road and other key city roads was on a gridlock as hundreds of his supporters, the majority on foot, attempted to force their way into the airport to welcome him.
The traffic mess continued for the better part of the day forcing Mr Odinga's convoy to leave JKIA driving on the wrong side of Mombasa Road. He was accompanied by a host of Nasa leaders and supporters on foot.
Kenya Airways noted that although its flight operations were running as scheduled, the traffic disruption resulted in some of its passengers missing their flights.
The airline offered to rebook the affected passengers without charging extra fees.
"Our operations are running as scheduled. Any guest who will miss their flight will be rebooked on the next one, at no fee. This applies to all guests travelling before 1800h, from JKIA, for tickets purchased on or prior to Friday, November 17, 2017," said Kenya Airways on its Twitter page.
Dozens of international flights depart and arrive daily at Nairobi's main airport. The national airport authority said on Twitter just before midday that operations were running normally.
Mr Odinga's convoy later diverted from Mombasa Road, a key highway that links the port of Mombasa to landlocked countries in East and Central Africa, to Jogoo Road in the eastern side of Nairobi heading for Haile Selassie Avenue. The opposition planned to hold a rally at the city centre's Uhuru Park at the junction of Haile Selassie Avenue and Uhuru Highway.
But a heavy police deployment blocked roads leading into the main business district and broke up crowds surrounding the convoy, unleashing teargas and water cannon and firing shots in the air.
Clashes between the police and the Nasa supporters brought business to a standstill on the city roads that serve the eastern part of the capital.
For the better part of the afternoon, Jogoo Road was clear of traffic only littered with rocks that the Nasa supporters were throwing at the police.
Traders had closed shops and fled for safety.
A minibus, a police lorry and two pull-carts, popularly known as mkokoteni, were torched outside a market along the road.
Smoke from burning tyres billowed and seemed to compete with the teargas the police were firing.
The chaos took a different turn when a rival group believed to be ruling Jubilee supporters engaged with the Nasa group. They said they were opposed to Nasa protests which they argue disrupt businesses and lead to destruction of property and loss of lives.
Police used verbal orders, teargas, water canons and live bullets to restore calm and order on the road without much success.
A man was seen in pain on live TV after he was allegedly shot in the foot.
Mr Odinga won an unprecedented court victory overturning the result of the August 8 presidential poll, leading to a rerun last month that he then boycotted claiming it would not be free and fair.
Kenya's Supreme Court is due to rule Monday on whether President Uhuru Kenyatta can be sworn in for a second term or if there must be another rerun.
The dispute over this year's presidential vote has left the country deeply divided and protests between stone-throwing opposition supporters and riot police armed with tear gas, sticks and guns have become commonplace.
Following the rerun vote Nasa launched a "National Resistance Movement" aiming to use civil disobedience and boycotts to challenge what it considers to be Mr Kenyatta's illegal government.
Friday's gathering of thousands of opposition supporters in Nairobi was the movement's first show of strength since then, but fell short of the "million man march" promised by party leaders.
Originally published on Nation.co.ke; Additional reporting by the Business Daily, AFP and Reuters.