Pakistani police dispersed thousands of supporters of a radical Islamist party on Monday in Lahore (east) after the arrest of its leader a few hours earlier.
Saad Rizvi, the leader of Tehreek-e-Labbaik Pakistan (TLP), an influential extremist movement, has been arrested in Lahore, his party officials said.
His arrest was confirmed by the police, who did not specify the charges against him.
He had tried to organize a march on the capital, Islamabad, on April 20 to demand the departure of the French ambassador.
Thousands of protesters, who blocked streets and intersections in Lahore, Pakistan's second largest city, were dispersed by police using tear gas and water cannons, AFP said.
Anger around cartoons
In a video posted on social media, TLP deputy chief Syed Zaheer-ul-Hasan Shah said Saad Rizvi's arrest meant the government had violated an agreement to expel the French diplomat.
Saad Rizvi is the son of Khadim Hussain Rizvi, the former leader of the TLP, who died in November.
He was largely behind the often stormy anti-French protests that agitated Pakistan in the fall after the republication of the Prophet Muhammad cartoons by the French satirical weekly Charlie Hebdo.
The TLP had also mobilized thousands of demonstrators to protest against statements by French President Emmanuel Macron, who had defended the right to caricature in the name of freedom of expression, during the tribute paid to a teacher killed on the 16th October after showing his class satirical cartoons.
TLP supporters paralyzed the capital for three days last year with a series of rallies against France.