A second suspect wanted in connection with the killing of a police officer on the Champs-Elysees in Paris has handed himself in.
France's interior ministry said the suspect had walked in to a police station in Antwerp, Belgium.
Meanwhile, the attacker shot dead by police on Thursday evening is believed to be Karim Cheurfi, 39, who had a criminal record.
A property being searched in the eastern Paris suburb of Chelles is understood to be his home, according to a police document seen by the Associated Press news agency.
The attack happened when a car pulled up next to a police van, with a gunman getting out and immediately shooting at officers who were guarding an area near the Franklin Roosevelt metro station.
He tried to run along the pavement of the famous avenue, aiming at other police and hitting two of them, a French interior ministry spokesman said.
Other officers opened fire, killing the assailant.
As well as the two officers - who doctors now say are out of danger - a woman tourist was also wounded.
Islamic State claimed it was responsible for the attack and named Abu Yusuf al Beljiki as the attacker - though it is believed this could be a pseudonym for Cheurfi.
Security has been tight in France, coming just days before the first round of the presidential election on Sunday.
A witness, who identified himself as Chelloug, said he heard six shots.
He said: "I thought they were firecrackers. In fact, he (the gunman) was hidden behind the van and shooting at the police.
"I think he hit a policeman. As soon as the policeman opened the door of the van, he fell."
He said he and tourists fled to a shop. "We saw the policeman shoot the gunman who could have killed more of us."
Another witness identified only as Ines told France's BFM TV she heard a shooting, saw a man's body on the ground and the area was quickly evacuated.
In the hours after the attack officers were seen pointing their weapons at members of public as they cleared the area.
Matthias Fekl, the French interior minister, paid tribute to the dead policeman and praised his colleagues who he said had "prevented a bloodbath".
He said: "Their composure, their perfectly adapted response in the decisive seconds, it all played itself out and prevented a bloodbath that could have been extremely widespread, extremely strong, on the Champs Elysees.
"Once again all our thoughts are with the policeman who was assassinated, cowardly, savagely, in a despicable act, an act that shook up our country."
Sky's Mark White said: "All the indications are that it was a terrorist attack."
He added: "Two men were arrested a few days ago with an arsenal of weapons. And that there was a concern that an attack was being planned to coincide with the French election."
Several candidates in Sunday's presidential election ended their campaigns early as a mark of respect, with the centre-right's Francois Fillon calling on others to do the same.