A statement by the NBA President, Abubakar Balarabe Mahmoud (SAN) said, "The Nigerian Bar Association condemns this brazen and blatant act of the security personnel and demands the immediate withdrawal of this personnel".
The most senior director at the DSS, Matthew B. Seiyefa, who was named as the acting head of the agency, met briefly with the acting president at the State House yesterday.
Osinbajo condemned the unauthorized takeover of the National Assembly complex, describing it as "a gross violation of constitutional order, rule of law and all acceptable notions of law and order".
Parliament began a two-month recess on July 24.
This is coming up after the Senator representing Kwara South, Rafiu Ibrahim, had alleged that senators belonging to the Parliamentary Support Group, PSG, received the sum of $1m each to impeach Senate President Bukola Saraki and his Deputy, Ike Ekweremadu.
The blockade followed the defection of around 50 lawmakers from Buhari's ruling All Progressives Congress (APC) party to the main opposition in the last few weeks.
Party primaries are due between this month and October, coinciding with mounting discontent at Buhari's style of government and handling of widespread violence across the country.
The security operatives, however, later allowed the lawmakers access into the complex while journalists and other staff were barred.
Police and the DSS did not return repeated calls asking for an explanation for the high-profile operation.
A Nigeria Police Force spokesman could not immediately be reached for comment.