A third man has been detained for questioning in connection with the knife attack at a church in the southern French city of Nice, which left three people dead, the AFP reported on Saturday. 

The man, 33, was present during a police search late Friday at the home of a second man suspected of having been in contact with the attacker, a young Tunisian. "We are trying to clarify what his role is in all this," a source told the AFP.

Read more: Terror attack in Nice: What we know