The French interior ministry has said four suspected Islamic militants arrested on Monday were "without doubt" planning at least one attack.

The ministry said all four had declared their support for a holy war and that two had admitted undergoing training with Chechen rebels in Georgia's Pankisi Gorge.

The arrests were made in a northern Paris suburb on Monday.

Police seized chemicals and suspected detonator components from one of the apartments raided, as well as a suit to protect against nuclear, chemical and biological attack.

"Even though none of those detained has confessed to planning an attack, there is no doubt that, given what has been found, one or several terrorist attacks were being planned in the relatively short term," the statement said.

Strasbourg link

It added that the chemicals could not have been used for a chemical attack, as had been originally supposed, but were used for making electronic circuits.

The BBC's James Coomarasamy in Paris says the information gleaned since the arrests confirms French intelligence suspicions about a strong Chechen connection to Islamic militancy in Western Europe.

One of those arrested was named as Merouane Ben Ahmed, aged 29, of joint French-Algerian nationality.

The statement described him as a "former commander from the Algerian (Islamic) armed opposition and a veteran of Afghanistan and Chechnya".

He has been on the wanted list for two years, after his name was linked to a group that allegedly plotted to blow up Strasbourg cathedral in December 2000.

Canisters

Investigators say Mr Ben Ahmed has also been in touch with Rabh Kadre, an Algerian arrested in Britain last month amid reports of a planned chemical attack on the London underground, and also with another man detained in the UK, Abu Daoud.

Mr Ben Ahmed's wife is also among the four held.

Among the list of items found at the premises raided on Monday, the ministry mentions gas canisters, said to be of a type used in a wave of bombings in France in the 1990s.

It says there were also false identity documents and $25,000 in dollar and euro notes.