French authorities said on Friday they feared a serial killer was on the loose after a gunman shot dead a 47-year-old mother near her home in a Paris suburb, using a weapon employed in three other killings in the same area within the last five months.
"This series of killings deserves our maximum attention and we are putting all our resources into this affair," Interior Minister Claude Gueant told Europe 1 radio.
In each of the four shootings, the first of which was in November, a lone gunman used the same 7.65 mm caliber semi-automatic pistol, prosecutors said. The latest shooting took place on Thursday when a gunman on a motorbike struck.
"It was a pistol, a semi-automatic pistol," said Marie-Suzanne Le Queau, public prosecutor in Evry, a commune in the southern suburbs of Paris. "This element alone is not enough to affirm at this stage that it is all part of the same affair."
There were obvious similarities in the way the latest three killings were carried out in February, March and April, but no clear link to the first killing in November, she added.
Around 100 investigators were working on the case and police were examining several leads, she said. The woman was a widow and had an 18-year-old son, Le Monde reported.
Reuters contributed to this report.
More from msnbc.com and NBC News:
- Horns worth more than gold: Rhinos face worst year
- Myanmar's Christian minority still fighting civil war
- 'We, the people': Mali rebels declare independence
- Christian, Jewish holidays intersect Friday
- Ditch the umbrella? 20 million in England hit by drought
- Libyans flock to beaches once preserved for Gadhafi elite
- Millionaire's daughter drove looters around during London riots
- Report: US democracy workers detained in UAE
Follow us on Twitter: @msnbc_world