Nigeria, March 6 -- The Senegal government on Friday vowed to use "all means necessary" to return order after police fired tear gas in clashes with supporters of opposition leader Ousmane Sonko as the interior minister said four people had died.

The clashes followed a court ruling that Sonko be held in custody. And following two days of protests, UN Secretary-General Antonio Guterres urged all sides to avoid any further escalation of the violence.

"The protests must remain peaceful, and the security and police forces must at all times operate. in line with international human rights standards," his spokesman, Stephane Dujarric, told reporters in New York.

"The government regrets the loss of four lives" in events "that are rooted in ban...