French police have arrested 12 people in two separate counterterrorism raids, amid a state of high alert for attacks in the country.
Nine people arrested in Marseille, the southern port city, on Tuesday morning were being investigated for suspected links to a "terrorist enterprise", police said.
Weapons including a Kalashnikov rifle, a pump action shotgun and ammunition were also seized in the raid, an official was quoted by the AFP news agency as saying.
Another three men were arrested in Marseille and Bordeaux, in France's southwest, on alleged ties to a group recruiting fighters for Afghanistan.
The trio were linked to Ryad Hannouni, a Frenchman arrested in the Italian city of Naples last weekend and suspected of being connected to al-Qaeda fighters, police said.
Officials said investigators wanted to question Hannouni on suspected links to armed fighters coming to Europe from Afghanistan, the AFP news agency reported.
The arrests come days after the US state department and a number of other governments warned of an increased risk of attacks in Europe.
France recently said it was on high alert, with the government warning that the country faces a serious threat of attack.
False alerts in recent weeks have prompted evacuations of train stations and Paris's Eiffel Tower.
Last month five French nationals were among seven people kidnapped, by the Northern African wing of al-Qaeda last, and continue to remain held hostage.
The arrests also come as reports suggest five German have been killed in a suspected drone attack in Pakistan that killed a group of fighters.
The are concerns that growing numbers of fighters are going from the West to remote war zones for training with al-Qaeda.
Brice Hortefeux, the French interior minister, said the threat of an attack in the country was "real".
"Yes there is a terrorist threat at the moment in Europe. It must be neither overestimated nor underestimated," he said.
"The threat is real, our vigilance is total and every French person must know that we're doing everything to ensure their security and their protection."
Hortefeux said he would take stock of the situation again on Thursday with European Union counterparts meeting in Luxembourg.
Intelligence reports have said well-armed teams of fighters planned to seize and murder Western hostages in a manner similar to the attacks two years ago in the Indian city of Mumbai on two hotels and its main railway station.