SAN SEBASTIAN, Spain (AP) — Thousands of Basque separatist sympathizers held a rally in northern Spain on Saturday celebrating the release from prison of a prominent regional leader four days after he completed a more than six-year sentence for trying to resurrect the banned political wing of armed group ETA.

Arnaldo Otegi, who was considered the political leader of the pro-Basque independence movement before his 2009 imprisonment, was greeted by more than 8,000 supporters inside the Anoeta cycling arena in the city of San Sebastian.

"They won't stop us until we've obtained our independence," he told his cheering supporters. A large screen placed outside the building conveyed images of the event to hundreds of supporters who hadn't been able to fit inside.

Otegi had entered the venue to loud music, flanked by traditional regional folkloric dancers.

There had been speculation that Otegi might present himself as a candidate for regional president in local elections later this year, although his sentence bans him from holding office until 2021.

However, he didn't say if he would put himself forward for election.

Batasuna was banned in 2003 on the grounds it was part of ETA, which killed 829 people over its decades-long campaign for Basque independence. The court ruled that Otegi had tried to form a new Batasuna under ETA's orders.

Although ETA announced what it called "a permanent cease-fire" in 2011, it has yet to disarm.

During his trial, Otegi argued that his group had persuaded the pro-ETA Basque separatist community to eschew violence.

While pro-secession sentiment has surged in Spain's northeastern Catalonia region in recent years, it appears to have lost much of its impetus in the Basque region, and many of its supporters are believed to be switching to the new far-left, anti-austerity political group Podemos.

Harold Heckle in Madrid contributed to this report.