* Opposition party promises more protests if demands not met
* Biggest demonstration since post-election unrest in 2005
By Aaron Maasho
ADDIS ABABA, June 2 (Reuters) - About 10,000 Ethiopians staged an anti-government procession on Sunday in the first large-scale protest since a disputed 2005 election ended in street violence that killed 200 people.
The demonstrators marched through Addis Ababa's northern Arat Kilo and Piazza districts before gathering at Churchill Avenue in front of a looming obelisk with a giant red star perched on top, a relic of Ethiopia's violent Communist past.
Some carried banners reading "Justice! Justice! Justice!" and some bore pictures of imprisoned opposition figures. Others chanted, "We call for respect of the constitution".
A few police officers watched the demonstration, for which the authorities had granted permission.
"We have repeatedly asked the government to release political leaders, journalists and those who asked the government not to intervene in religious affairs," said Yilekal Getachew, chairman of the Semayawi (Blue) Party which organised the protests.
He said the demonstrators also wanted action to tackle unemployment, inflation and corruption.
"If these questions are not resolved and no progress is made in the next three months, we will organise more protests. It is the beginning of our struggle," he told Reuters.
Government officials were not immediately available for comment.
Ethiopian opposition parties routinely accuse the government of harassment and say their candidates are often intimidated in polls. The 547-seat legislature has only one opposition member.
Though its economy is one of the fastest-growing in Africa, Ethiopia is often criticised by human rights watchdogs for clamping down on opposition and the media on national security grounds, a charge the government denies.
Critics point to a 2009 anti-terrorism law that makes anyone caught publishing information that could induce readers into acts of terrorism liable to jail terms of 10 to 20 years.
Last year, an Ethiopian court handed sentences of eight years to life to 20 journalists, opposition figures and others for conspiring with rebels to topple the government.
More than 10 journalists have been charged under the anti-terrorism law, according to the Committee to Protect Journalists, which says Ethiopia has the highest number of exiled journalists in the world.
Muslims, who form about a third of Ethiopia's mostly Christian population, staged mosque sit-ins in 2012, accusing the government of meddling in religious affairs and jailing their leaders.
Ethiopia, long seen by the West as a bulwark against radical Islamists in neighbouring Somalia, denies interfering, but says it fears militant Islam is taking root in the country. (Reporting by Aaron Maasho; Editing by George Obulutsa and Alistair Lyon)