The officers were delivering duly signed Form 34 and 33 capturing the results to be announced by the commission later on Wednesday.
Only 13,000 polling centres had relayed their results electronically giving Jubilee flagbearer Uhuru Kenyatta a lead with 2,790,417 with Cord's Raila Odinga trailing with 2,199,092.
About 11.5 million Kenyans took part in the elections.
Mr Odinga had secured 25 per cent in 31 counties while Mr Kenyatta had also garnered 25 per cent in 32 counties.
Analysts predicted the election could go either way with both Mr Odinga and Mr Kenyatta registering strong wins in their strongholds.
Earlier IEBC chairman Mr Ahmed Issack Hassan directed that all Returning Officers be summoned to the city to deliver results without fail.
Up to 70 Returning Officers from various constituencies around the country had arrived at the Bomas of Kenya by 3am on Wednesday and were queuing to file their returns before the results they delivered could be accepted.
“IEBC puts rapid transport measures to ensure Returning Officers deliver official results by early morning. This should tremendously increase poll results by mid-morning Wednesday March 6,”read a text message dispatched by the commission.
The commission would largely rely on the physically delivered results after the visualisation of the electronic results transmission facility they were using collapsed.
Party agents were also available at the tallying centre to carefully verify and reconcile the results as they were submitted by the commission officials.
Cord team at the Bomas of Kenya comprised of cabinet ministers James Orengo, Franklin Bett, Assistant minister Gideon Ndambuki and the ODM chief agent Prof Larry Gumbe.
The Jubilee team also comprised cabinet minister Charity Ngilu, Moses Kuria, Johnson Sakaja among others.
The IEBC had come under pressure from the two main political parties to release results to avoid raising tension in the country due to the uncertainty.
Various IEBC commissioners would be announcing results at intervals at the Bomas Of Kenya auditorium from early Wednesday.
“We have set teams here who will be coming to announce results as they come to us from the ground,” the IEBC chairman Ahmed Issack Hassan said.
The commission would be struggling to release all the results from all the 290 constituencies.
The Constitution however requires that all results delivered by the Returning Officers are properly verified before they can be officially declared.