Kenya's main international airport was experiencing flight delays on Monday due to a strike by members of the aviation union, operator Kenya Airports Authority said.
Nairobi's Jomo Kenyatta International Airport is one of the continent's major air transport hubs.
The labour dispute between the aviation workers' union and the civil aviation authority is over grievances including the failure to conclude a collective bargaining agreement.
Last week, the aviation workers' union issued a seven-day strike notice, after which the Kenya Civil Aviation Authority approached the courts to try to block the strike.
"This is a complete strike action. I have not been served with any court order halting the strike," Moss Ndiema, the union's secretary general, told Reuters by phone.
Kenya Airways and Tanzania's Precision Air said air traffic control delays were affecting departures and arrivals at Jomo Kenyatta International Airport.

Kuwait air defences deal with Iranian missile, drone attacks
US and Iran exchange attacks as lull in war appears over
Malta court clears businessman over murder of investigative journalist
Kuwait confirms no injuries after Iranian drone hits residential complex
Nepal flood rescue hopes dim as China restores access to Tibet disaster zone
At least 21 die in bus accident in Egypt's South Sinai, ministry says
Defendant pleads not guilty in Charlie Kirk capital murder case
Nepal flood death toll crosses 1,000, rescuers reach remote areas
