French police said Saturday that two people had been arrested after the Lens team bus was vandalised while parked outside their Paris hotel ahead of a Ligue 1 game against Paris Saint-Germain.

Images on social networks and French media showed the bus, which has a huge Lens logo, smeared with yellow graffiti saying "PSG", "Paris SG", "Ultras Paris" and another insulting Lens.

The two people were arrested after the attack, a police source said, without giving further details.

Lens said they would not comment because they "wanted to concentrate on our match" but indicated that they might press charges.

PSG, second in Ligue 1, host fifth-placed Lens on Saturday afternoon in a crucial duel in the race for the title and European places.

The incident follows an infamous banner displayed by PSG fans at the 2008 French League Cup final between the clubs.

It attacked 'Ch'tis', as people from the northwest corner of France are known, saying "Paedophiles, unemployed, inbreds: welcome to the Ch'tis"

Five fans were convicted in the case, fined and banned by PSG.

PSG released a statement on Saturday supporting Lens.

"Paris Saint-Germain condemns in the strongest possible terms the intolerable acts committed against RC Lens by individuals claiming to be supporters of the club," PSG said in Saturday's statement.

"Police investigations are underway. The club reserves the right to take all appropriate sanctions and legal measures if it appears that some of its supporters are associated with these shameful acts," PSG added, saying it offered "support and sympathy for RC Lens and its fans".

A Lens representative said the bus has been cleaned up, although there are still some traces of the graffiti.