France admits 'failings' over Paris police attacker's radicalisation

France's interior minister acknowledged Sunday that officials should have kept a closer eye on the Paris police employee who stabbed four colleagues to death last week, after investigators found evidence he had supported an extreme version of Islam.

"Obviously, there were failings," Christophe Castaner told TF1 television, but he said he would not resign over the matter as some rightwing opponents have said he should.

Castaner has come under fire after initially claiming that Mickael Harpon, a 45-year-old computer expert at the Paris police headquarters, had never given the "slightest reason for alarm" ahead of Thursday's attack.

Investigators later revealed that Harpon had in fact been in contact with adherents of Salafism, the ultra-conservative branch of Sunni Islam.

He had defended "atrocities committed in the name of that religion," anti-terror prosecutor Jean-Francois Ricard said Saturday.

On Sunday, Castaner said Harpon had caused alarm among his colleagues as far back as 2015,