SAINT-DENIS, France — French police hunting the suspected ringleader behind the Paris massacre raided another terrorist cell Wednesday which was plotting a new strike — but the fate of the man being sought was unclear.

Paris prosecutor Francois Molins said at least two suspected terrorists — a man and a woman — were killed, and eight more were arrested in the early morning raid on an apartment in the suburb of Saint-Denis.

Neither Belgian jihadi Abdelhamid Abaaoud, who is believed to have played a key planning role in the assault on Paris, nor fugitive suspected accomplice Salah Abdeslam are among those who were arrested, the prosecutor said.

Molins said the dead "have not been formally identified."

"I can say Abaaoud and Salah A. are not among those in custody," the prosecutor said.

NBC News could not immediately confirm a report in The Washington Post saying Abaaoud had been killed in the raid.

Molins said the raid was the result of information that a building might contain a possible hideaway of Abaaoud in a third-floor apartment.

The elite police unit pursuing Abaaoud was met with fierce resistance. Officials believe the woman blew herself up with a suicide belt during the dramatic hours-long battle, in which police fired some 5,000 rounds.

Five police officers were injured and a police dog named Diesel was killed. Molins did not say whether some attackers might still be on the loose, and he gave no details on what other mayhem the terrorists were planning.

PHOTOS: Police Target Paris Attack Suspects in Saint-Denis Raid

Interior Minister Bernard Cazeneuve told the French national assembly that it was possible there was a third body from the raid, and that investigations — "including DNA analysis" — were still underway.

"It's possible that Abdelhamid Abaaoud was in the apartment this morning," Cazeneuve's spokesman Pierre Henry Brandet told local media.

Heavy gunfire was heard for several hours beginning around 4:30 a.m. local time (10:30 p.m. ET Tuesday) in the northern district of Saint-Denis.

Veronique Haounoh, 43, was holed-up in an apartment across the street from the operation with several neighbors and heard "explosions at irregular intervals."

"We heard so many booms," she told NBC News. "I'm shaking. We are very scared, I can't stop crying."

Witness Abdel Nour al Jazaeri, an unemployed Algerian immigrant, told NBC News that he saw police raiding a building and heard intense gunfire beginning at 4:30 a.m.

A local resident who lives nearby said that he heard "lots of shots" between 4:30 a.m. and 6:30 a.m. local time.

"I was sleeping," said the man, who identified himself only as Alexandre. "I heard the noise — the shots. I said, 'That's not fireworks'."

What sounded like a single gunshot rang out as police continue raid, cordon outside paris pic.twitter.com/gn9Re8zz2Y — Richard Engel (@RichardEngel) November 18, 2015

Some people who lived nearby were rousted from their beds by police and rushed out of their homes clad in just their underwear or pajamas.

Gloria Mukenga, 28, lives a few blocks from where the raid took place. She recorded a man being cornered by police with protective shields, hours after the pre-dawn raid. One officer shouted at the man in English: "On your knees! Show me your back." It is unclear if he was one of the eight detained.

"We all thought they [terrorists] were gone, to think that they were right next to us all along," Mukenga told NBC News.

Saint-Denis is a mostly low-income area that's close to the Stade de France, a 81,000-seat venue which was targeted by three suicide bombers during a game involving the national team and Germany on Friday.

Police said they were following the female suspect, who was believed to have a connection to the terrorists. The subsequent operation involved 110 officers from France's elite RAID unit.

Local resident Jawad Ben Dow told Reuters that the standoff was centered on his apartment.

He added: "Someone asked me to put two people up for three days and I did them a favor, it's normal. I don't know where they came from I don't know anything. If I'd known do you think I'd have done it?"

Mathieu Hanotin, a local lawmaker, described the operation as a "big victory."

When asked if he thought the suspects at the apartment were planning another attack, Hanotin said that remained unclear but added their weapons showed "they were ready."

Authorities have been searching for more suspects believed to have participated in Friday's series of bombings and shootings. Seven attackers were killed, most in suicide bombings, officials said.

Police had already been looking for Salah Abdeslam, 26, believed to have been an accomplice in the attacks. His name was on rental documents for a black Belgian-registered Volkswagen found outside the Bataclan concert hall, where 89 people were killed. He is the brother of one of the dead attackers, officials said.

French officials told The Associated Press that an analysis of the attacks indicated one additional person directly involved in the onslaught remains unaccounted for.

Related: Who Was Killed in Paris Attacks, and Who's Still On The Run

Meanwhile, the Parisian newspaper L'Express reported that a 52-year-old man named Stéphane Hache was killed by a stray bullet. He lived behind the Le Bataclan concert hall.

Tuesday night, two Air France passenger jets leaving from the U.S. for Paris were diverted after bomb threats were phoned in, the airline said.

Both planes landed safely — a flight from the Washington, D.C., area in Halifax, Nova Scotia, and a plane from Los Angeles in Salt Lake City, Utah, officials said.

Also Tuesday, a soccer stadium in Germany packed with thousands of fans was abruptly evacuated because of a "potential threat to spectators," police said.