PARIS (AFP) - Two Belgians arrested in France after allegedly fleeing police raids against an Islamist cell in their home country were headed towards Italy, police sources said Friday.

The suspects left Belgium shortly after security forces launched an assault in the eastern Belgian town of Verviers on Thursday night which reportedly foiled a plot to carry out attacks against the police.

They were arrested in Chambery in eastern France as they were just about to cross into Italy, a police source told AFP.

"They were crossing the border at the exact moment that customs officers received the file from Belgium and were detained," a separate police source confirmed.

Two suspects were shot dead in Verviers and 13 arrested across Belgium in the raids against an Islamist cell.

"The group was on the verge of carrying out terrorist attacks to kill police officers on public roads and in police stations," Belgian federal prosecutors' spokesman Eric Van der Sijpt told journalists.

The group, which had recently returned from Syria, had Kalashnikov assault rifles, explosives, ammunition and communications equipment, along with police uniforms, he said.