The Philippines has jailed a Spanish man after he was convicted for weapons possession, nearly five years after his arrest, the Philippine justice department said Thursday.

Army counter-terrorism troops in January 2018 arrested Abdelhakim Labidi Adib, 20 at the time, at a checkpoint on the southern island of Basilan, a stronghold of armed Islamist militants.

They alleged Labidi Adib, a Spanish citizen of Tunisian descent who described himself as a tourist, carried grenades and bomb-making equipment in his backpack.

They also accused him of being a sympathizer of Abu Sayyaf, a local armed rebel group with ties to the Islamic State that has been blamed for deadly bombings and beheadings of kidnap victims.

A second man who was accompanying the convict escaped, authorities said.

Labidi Adib agreed to plead guilty to charges of three counts of possession of a loaded small arm, for which a Basilan court gave him prison terms of between eight and 14 years each, the justice department said in a statement.

Under the Philippines' penal code, multiple penalties are served simultaneously in order of severity, with the maximum duration not more than three times the length of the most severe one.

"Justice Secretary Jesus Crispin 'Boying' Remulla lauded state prosecutors for securing the conviction of a suspected terrorist," the statement added.

Labidi Adib was arrested eight months after Abu Sayyaf gunmen along with other pro-Islamic State allies seized the center of Marawi city, the main Muslim city in the mainly Catholic nation.

The attack sparked a five-month battle that destroyed much of the city and left more than a thousand people dead, before the city was recaptured by Philippine forces with intelligence assistance from the US military.

Labidi Abid arrived in the Philippines in October 2017, around the time that the Marawi siege ended, the military had said earlier.