US Democratic presidential contenders Elizabeth Warren and Bernie Sanders clashed over whether he once told a woman she could not become president.
While Sanders emphatically denied he had ever made the remark, Warren refused to back down about what he had said during a private 2018 meeting with her.
The two were seen engaging in a tense discussion after the debate, thus underlining an emerging rift between the progressive contenders as the first voting nears.
During the debate in Iowa, they were also seen disagreeing on foreign policy and trade.
Apart from the two senators, opinion polls showed former Vice President Joe Biden and former South Bend Mayor Pete Buttigieg in an extremely tight race.
Philippines confirms visit by alleged Bondi gunmen amid terrorism concerns
Israeli forces kill Palestinian teen in West Bank, health ministry says
Trump sues BBC for defamation, seeks up to $10 billion in damages
FBI foils 'terror plot' targeting Los Angeles
Hong Kong court finds tycoon Jimmy Lai guilty in landmark security trial
Ukraine peace talks stretch into second day at start of pivotal week for Europe
Flash floods kill at least 37 people in Morocco's Safi province
'Hero' who disarmed Bondi gunman recovering after surgery, family says
