French police were negotiating Friday with two sets of gunmen who are believed to have taken hostages in two separate but linked incidents two days after the deadly terrorist attack in Paris. The sounds of gunshots and loud explosions at both sites could be heard on local television broadcasts Friday evening.

Saïd and Chérif Kouachi, the prime suspects in the killing of 12 people at the offices of the satirical newspaper Charlie Hebdo on Wednesday, were located by police northeast of Paris and then chased to a factory on an industrial estate where they are believed to have taken one hostage. French officials said they had made contact with the brothers who told them that they want to die as martyrs.

As that siege unfolded, a man believed to be Amedy Coulibaly, 32, a suspect in the fatal shooting of a policewoman on Wednesday, attacked customers at a kosher supermarket near the Porte de Vincennes in the east of Paris. Local media said several were injured and at least two killed in the shooting before Coulibaly took refuge in the supermarket with at least five hostages.

Police assumed the Wednesday shooting was just a tragic coincidence, unrelated to the Charlie Hebdo massacre. But on Friday, Prime Minister Manuel Valls told reporters that the two incidents were in fact connected, and that the shooter had communicated with the Kouachi brothers—suggesting that Wednesday’s attack might be part of a bigger plan. “The latest advances in the investigation allows us to establish a connection” between the two incidents, Valls said on Friday afternoon, while he was meeting the grief-sticken staff members of Charlie Hebdo, at the offices of the French daily newspaper Libération.

Police said they were also looking for Hayat Boumeddiene, 26, in connection with Wednesday shooting. It is not clear if she was with Coulibaly at the Porte de Vincennes. Le Monde reported that Boumeddiene was Coulibaly’s former girlfriend.

Earlier in the morning, Saïd and Chérif Kouachi, aged 34 and 32, fled the wooded areas further of Paris in a Peugeot car they hijacked on the road, according to French media reports. Shortly after there was sounds of gunfire, as the suspects fled towards CTF Creation Tendance Decouverte, a sign making and printing factory in an industrial zone close to Paris’s main airport.

For the first time since Wednesday, French officials sounded confident that they were close to a climax in the manhunt. Interior Minister Bernard Cazeneuve told reporters on Friday morning that SWAT teams had the men cornered in the factory in Dammartin-en-Goèle and that special forces were on site, ready to move in. “Operations will be conducted in the hours, the minutes,” he said shortly after 10 a.m.

France Info radio interviewed a man who gave his name as Didier who said he went into the factory when the gunmen were there. He had an appointment with the factory manager and he shook the hand of one of the gunmen who he took to be a police officer. “We all shook hands and my client told me to leave.” Didier said the gunman told him: “Go, we don’t kill civilians”. He added “I thought it was strange.”

He said: “As I left I didn’t know what it was, it wasn’t normal. I did not know what was going on. Was it a hostage taking or a burglary?”

Christelle Alleume, who works across the street, said that a round of gunfire interrupted her coffee break Friday morning.

“We heard shots and we returned very fast because everyone was afraid,” she told i-Tele. “We had orders to turn off the lights and not approach the windows.”

Prime Minister Manuel Valls has said both men were known to intelligence services.

On Thursday evening French officials told the U.S. that Saïd Kouachi had traveled to Yemen in 2011 and received weapons training from Al-Qaeda in the Arabian Peninsula (AQAP). Anwar al-Awlaki, a leader of AQAP died in a U.S. drone attack that same year. The younger brother Chérif spent 18 months in jail in 2008 for having attempted to fight with jihadist groups against U.S. forces in Iraq. Police had monitored his radical views for years. By contrast to his brother, Saïd had managed to escape arrest so far. Cazeneuve said on Thursday that the older Kouachi brother “has never been prosecuted or convicted, but has appeared on the periphery of judicial cases.”

The head of Britain’s MI5 security agency said on Thursday that British intelligence believed terror networks were actively planning “complex and ambitious plots” against Western targets. Speaking at MI5 headquarters in London, Andrew Parker told members of the Royal United Services Institute, a defense and security think tank, that those fighting in Syria were currently plotting assaults abroad. “We know, for example, that a group of core al-Qaeda terrorists in Syria is planning mass casualty attacks against the West,” he said.

Malcolm Rifkind, a British legislator and chairman of the House of Commons intelligence and security committee said the brothers had been in close contact with associates in Yemen in recent days. “What is emerging in Paris is that the two individual responsible for the terrible massacre at Charlie Hebdo were communicating with people in the Yemen over the last days, last few weeks,” he told the BBC.

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