Paris has evidence of Syrian government troops using cluster bombs, French Foreign Minister Laurent Fabius said on Wednesday.

“Yes, we have evidence of the use of cluster bombs even though the regime denies that,” he said.

Cluster bombs, which scatter hundreds of bomblets before exploding, are controversial because of their potential to inflict civilian casualties over a wide area.

Fabius also said continued fighting in Syria could lead to an increase in the influence of extremists, whose number is insignificant at present.

“This is an argument that I used in negotiations with [Russian Foreign Minister Sergei] Lavrov. He says that we cannot get rid of Assad because that will lead to chaos and jihadists,” Fabius said.

“My response is that chaos is already there, and if you continue opposing regime change the danger is that extremists will increase their influence.”

Lavrov denied on Monday reports that Syrian authorities used Russian-made cluster bombs against rebels.

The New York-based Human Rights Watch (HRW) has said that during the ongoing conflict in Syria Russian-made RBK-250 series cluster bomb canisters with AO-1SCh fragmentation bomblets were used by the government troops against the rebel forces.

Seventy seven countries signed a convention in 2008 to ban the use of cluster bombs, which were actively used by the United States during a 1999 military campaign in Yugoslavia. However, Syria, as well as Russia, the United States and China did not sign the convention.

The Syrian conflict has claimed tens of thousands of lives, according to various Syrian opposition groups. The UN puts the death toll at over 20,000 people.