Tirana: A bus carrying Serbia’s national football squad was hit by stones within hours of the team arriving in Albania on Wednesday for a Euro 2016 qualifier, a year after their previous encounter was abandoned in chaos.

Albania has stepped up security for the politically-charged match, after their first meeting in Group I in Belgrade was abandoned when a drone carrying a flag depicting ‘Greater Albania’ flew over the stadium and a brawl ensued between players.

The Balkan countries have long been at odds over Serbia’s majority-Albanian former Kosovo province, which declared independence in 2008 almost a decade after Nato went to war to halt the massacre and expulsion of civilians during a Serbian counter-insurgency war.

Serbia’s foreign ministry said it had prepared a protest note over the incident, in which stones struck the bus as it drove into the Albanian capital, Tirana, cracking a window. Video broadcast on Serbian media showed streets lined with people, and at least two stones striking the bus.

“Lower your heads, heads down,” a voice was heard saying inside the bus. No one was hurt, but Serbia said the incident raised doubts over security for the game on Thursday evening in the central Albanian town of Elbasan.

Tomislav Karadzic, the president of Serbia’s football federation, commended the Albanian police for securing the route from the airport to the hotel.

But, he said, “several rocks were hurled from the crowd towards the bus. A sizeable one landed in the vicinity of the second or third row of seats, where our players were sitting.

“If this level of security remains unchanged, there will be problems. But they [Albanian police] have guaranteed that this will not happen again. We are waiting to see what happens next.”

Serbia’s foreign ministry said it had summoned Albania’s ambassador, Ilir Bocka, but that he had refused to receive Serbia’s protest note. There was no immediate word from the Albanian embassy.

Albania has put up 1,800 policemen to ensure security at the match. The man behind last year’s drone incident was arrested on Wednesday in Albania in possession of a pistol and 36 match tickets despite himself being banned from the game.

Like their Albanian counterparts in the first game, Serbian fans are barred from attending Thursday’s tie, with the exception of 70 students.

“We know that there is tension, that all eyes are on this game, that some want to turn it into something that is not football,” Serbian caption and Chelsea defender Branislav Ivanovic told reporters. “We know we face a cauldron; we don’t expect the applause of the Albanian fans.”