By Ece Toksabay and Huseyin Hayatsever ANKARA (Reuters) -Turkish authorities released a lawyer for jailed Istanbul Mayor Ekrem Imamoglu, President Tayyip Erdogan's main political rival, after detaining him overnight,

Turkish authorities detained and deported BBC correspondent Mark Lowen​ and arrested other journalists amid the largest nationwide protests in a decade.

Turkey's justice minister said on Thursday the decision to arrest Istanbul mayor Ekrem Imamoglu was based on criminal reports and not linked to the timing of the opposition CHP party's selection of Imamoglu as its presidential candidate.

A lawyer representing jailed İstanbul Mayor Ekrem İmamoğlu, Mehmet Pehlivan, was taken into custody early today.

Turkish authorities have detained 343 people during overnight protests in several cities against the detention of Istanbul Mayor Ekrem Imamoglu, the Interior Ministry said on Saturday.

President Recep Tayyip Erdogan's biggest political rival -- was arrested over graft and terrorism allegations, a video was shared in social media posts that falsely claimed it showed street protests in the Turkish city.

The head of Turkey’s main opposition party has visited jailed Istanbul Mayor Ekrem Imamoglu after six nights of massive protests calling for his release.

Secretary of State Marco Rubio said on Thursday he expressed to Turkish Foreign Minister Hakan Fidan U.S. concerns over the protests and detentions in Turkey following the arrest of Istanbul mayor Ekrem Imamoglu.