Paris — Both attackers who stormed a French church and killed an elderly priest had been on watch lists, authorities said on Thursday as new details emerged about the assailants’ apparent attempts to reach Islamic State territory in Syria.

The latest revelations about Tuesday’s attack are likely to add pressure on authorities over their protocol for monitoring suspected militants, as well as increase calls to boost intelligence services amid a greater shift to focusing on potential homegrown radicals rather than those returning from abroad.

French officials identified the second church assailant as Abdel Malik Nabil Petitjean, 19, a French native.

Petitjean was also known to French authorities since June 29 as a potential Islamist militant, police sources told the Reuters news agency, without giving details of the probes.

The other attacker, Adel Kermiche, also 19, had been required to wear an electronic ankle bracelet that allowed authorities to trace his movements.

Both had attempted to enter Syria from Turkey but were turned away, officials said.

Petitjean and Kermiche swept into the church in Saint-Etienne-du-Rouvray, a suburb of Rouen in the northern Normandy region, and slit the throat of Jacques Hamel, a beloved 85-year-old priest. The two attackers were later shot dead by police.