"Security reasons" have prompted Tunisia to ban people from wearing the full-face veil in public institutions, according to the TAP official news agency.
The rule applies to both staff and visitors and takes effect immediately.
On 27 June, twin suicide bombings rocked the capital, Tunis, targeting Tunisia's security forces. The first explosion involved a suicide bomber who targeted a police patrol on Tunis's central Charles de Gaulle Street. One police officer was killed, while another was wounded, according to the Interior Ministry. Three civilians were also wounded.
A second attacker blew himself up shortly afterwards near a national guard base in the capital's al-Qarjani district, with four security personnel wounded in that attack.
There have been reports that terrorists have been using the niqab, that covers everything but the eyes, to disguise themselves, TAP said.
The attack was the third such incident within a week and came at the peak of the tourist season as Tunisia prepared for an autumn parliamentary election.
In 2011, women were allowed to wear the hijab and niqab in Tunisia after a decades-long ban under secular presidents Zine El Abidine Ben Ali and Habib Bourguiba.
In February 2014, the interior minister instructed police to step up supervision of the wearing of the niqab as part of "anti-terrorism" measures to prevent its use as a disguise.
Tunisia had been battling armed groups operating in remote areas near its border with Algeria since the Arab Spring uprising saw the ousting of President Ben Ali in 2011.
Several European, African and Asian countries have issued full or partial bans on the wearing of veils over concerns about security.