Police officers rushed to secure the area and hunt for assailants after a guard was shot at the National War Memorial and several rounds were fired inside the Parliament building.
Juan Francisco Sáenz-Tamez, 23, was apprehended on Tuesday while shopping, officials said. An indictment against him was unsealed the same day.
North Korea said its leader, Kim Jong-un, had ordered the release of Mr. Fowle, one of three Americans recently detained there, after requests from President Obama.
As a fight over the city’s political fate unfolds, those who arguably have the most clout with Beijing and the most at stake have maintained a studied silence.
Even as Tunisians have approved a new constitution and the country has one of the Arab world’s most educated populations, militants are recruiting more openly there than in any other country.