Three months after Islamist terror attacks killed 17 people in and around Paris, France remains on high alert to anticipate other violent outbursts. On Wednesday, French Interior Minister Bernard Cazeneuve announced that police had apprehended a 24-year-old French Algerian computer science student who was planning an imminent attack on "one or two churches" in the Paris suburb of Villejuif.

Officers arrested Sid Ahmed Ghlam on Sunday following an accident in which he apparently shot himself in the leg and called emergency services. Ambulance workers alerted the police after transporting him to the hospital, which is standard protocol in the case of a gunshot wound.

According to reports, Ghlam first told police that he had been injured during a mugging. When investigators followed a trail of blood to the man's car and searched his home, Cazeneuve said that they found "an arsenal of several war weapons, handguns, ammunition, bulletproof vests, and computer and telephone hardware."

Paris prosecutor François Molins told reporters that the suspect eventually admitted to injuring himself while handling a firearm, and claimed that he was planning to dump the weapons in the river Seine. According to the prosecutor, Ghlam has remained "completely silent" since.

Molins revealed that officers seized four Kalashnikov assault rifles — one in Ghlam's car, three others in his student accommodation. According to French daily Le Parisien, officers also found a firearm that had been reported stolen by the police, a flashing police car light, and several police armbands.

In addition to weapons and equipment, documents written in Arabic that referred to al Qaeda and the Islamic State were found in the suspect's home.

Molins noted that Ghlam was in contact with a presumed co-conspirator who might have been based in Syria, who had specifically instructed him to target a church. The prosecutor said that the two of them had communicated in detail about how to carry out an attack. Investigators are now focused on tracking the accomplice.

According to Cazeneuve, data found on Ghlam's car navigation system and several handwritten notes establish "beyond doubt that the individual was planning an imminent attack, probably on one or two churches."

The interior minister added that police had linked the suspect to the mysterious murder of 32-year-old fitness instructor Aurélie Châtelain, who was found dead in her car in Villejuif on Sunday. She died of a single gunshot.

Châtelain, who has a five-year old daughter and had traveled to Paris to attend a Pilates training course, was discovered after passers-by reported her smoke-filled car to the police. Officers found that the smoke had been caused by the victim's overheating laptop.

A bullet retrieved from Châtelain's vehicle was traced to one of the weapons seized from the Ghlam's car. Investigators also found traces of the victim's blood on a jacket worn by the suspect. According to French daily Le Monde, police also discovered the suspect's DNA in Châtelain's car.

Ghlam arrived in France in 2009 under "family reunification" provisions, which allow legal immigrants to bring relatives to the country. According to Cazeneuve, the student had been under police surveillance since 2014, after he had expressed a desire to travel to Syria to wage jihad.

In 2015, the suspect spent a week in Turkey and was questioned by police upon his return. In his statement, Cazeneuve said that a police security warning had been issued at the time, but that there was not enough evidence to justify a judicial inquiry.

Terror expert Jean-Luc Marret, a senior researcher at the Foundation for Strategic Research and a senior fellow at the Center for Transatlantic Relations, told VICE News that an attack against a Christian site in France was to be expected, though he noted that there has never been a jihadist attack against one of the country's churches.

France's counterterrorism efforts, he added, lack the resources "to foil every single attack" on French soil.

"With thousands of churches in France, there is a capacity issue," Marret said. "I'm not sure we can protect all churches in the same way that we protect all French synagogues."

French officials have tightened security outside of Jewish schools, synagogues and other institutions since the January terror attacks.