Among those detained are a general and a colonel from the National Guard.
President Maduro has accused opposition politicians and neighbouring Colombia of plotting to kill him in a drone attack during a military parade in the capital Caracas on 4 August.
Chief prosecutor Tarek Saab said 12 other people were so far in detention.
Two drones loaded with explosives were detonated at the parade as the president was speaking.
Venezuela has issued 27 arrest warrants for the apparent attempt on Mr Maduro. Those arrested to date include a lawmaker and several young men.
The Venezuelan authorities say other suspects are still at large, many in neighbouring Colombia and the United States.
Mr Maduro accused Colombia and elements within the US of instigating "a right-wing plot" to kill him.
The Colombian government says there is no basis to Mr Maduro's allegations.
US National Security Adviser John Bolton denied any US involvement in the incident, adding that it could be "a pretext set up by the regime itself".
Mr Maduro has said he will allow US FBI agents into Venezuela to help investigate the alleged assassination attempt against him.
The country faces a deep economic crisis which has driven hundreds of thousands of Venezuelans abroad.
Many opposition leaders have already left the country citing government harassment.
There are reported to be more than 200 political prisoners in the country's jails.
In May, Mr Maduro won re-election to a second six-year term in a vote marred by an opposition boycott and claims of vote-rigging.