Updated

The Paris prosecutor's office says two people have been detained after a possible explosives laboratory was discovered in a suburb south of Paris.

The prosecutor's office said Wednesday that "elements that may be part of the composition of explosives" were discovered in an apartment in Villejuif.

The office says its special counter-terrorism section has opened an investigation under potential charges of "criminal terrorist association, possession, transportation and production of explosive substances in relation with a terrorist action by an organized gang."

Three police sources say a bomb-disposal operation is underway in the apartment. They spoke on condition of anonymity because of the ongoing investigation.