Italian police on Tuesday arrested two people as part of an investigation into a militant cell suspected of planning attacks in Rome and London, an investigative source said on Tuesday.

The cell had been established in Puglia, in southeastern Italy, "to carry out violent attacks with the purpose of international terrorism, in Italy and abroad", the arrest warrant read.

In all, the warrant calls for the arrest of five people, four Afghans and a Pakistani, three of whom are still at large. They are all officially resident near Bari, the main city in Puglia, but two are currently in Afghanistan, the source said.

Three of the suspects are accused of international terrorism and two of aiding illegal immigration.

Italy has not suffered deadly Islamist attacks like those in France and Belgium, but a number of people have been arrested on suspicion of planning assaults.

The group, whose members were arrested in Bari, are suspected of acting as a local unit or providing logistical support to an international organization linked to Islamic State, investigators wrote in the arrest order.

The organization was also active in France and Belgium, the order said. Their plans to attack focused on Rome and London.

Police confiscated the suspects' phones, on which they found footage of presumed targets including airports, ports, shopping centers and hotels. Investigators also found recordings of prayers and images of weapons and mutilated U.S. soldiers.