The Turkish capital, Ankara, is busy preparing for the NATO summit on July 7 and 8. The high-profile meeting is taking place amid international tensions, fueled in part by statements against the trans-Atlantic security alliance by US President Donald Trump.

Still, the summit is particularly important for Turkey as it has NATO's second-largest military and plays a central role on its southeastern flank. It also is the first visit by a sitting US president to Turkey in 17 years, after Barack Obama in 2009.

However, those preparations have been overshadowed by a wave of arrests. According to media reports, a total of 225 people have been arrested in recent days. Of those, 178 remain in pretrial detention. They include human rights and environmental activists, and journalists. A strict two-week ban on public gatherings has also been imposed in Ankara itself.

Turkish prosecutors bring allegations of terrorism

Turkish prosecutors have justified the crackdown by citing ongoing investigations into terrorist organizations. The goal, they say, is to uncover the organizations' activities across Turkey.