By Abdourahim Arteh
DJIBOUTI, Feb 26 (Reuters) - Djibouti security forces fought running battles with opposition supporters for a second day on Tuesday in an attempt to disperse protests against the ruling coalition's parliamentary election victory, witnesses said.
Djibouti hosts the United States' only military base in Africa and is an important ally in the U.S.-led fight against militant Islam. The former French colony's port is also used by foreign navies protecting the Gulf of Aden's shipping lanes, some of the busiest in the world, from Somali pirates.
Riot police fired tear gas to scatter hundreds of chanting demonstrators outside the Justice Ministry who were demanding the release of Sheikh Bashir Abdourahim, a prominent opposition figure whose family said he had been arrested on Monday.
"Not only did they steal our election victory, they're throwing into jail the people we voted for," Ali Saleh, a university student, told Reuters.
Protesters pledged to keep up the unrest until President Ismail Omar Guelleh's government collapses.
The dispute over the poll raises the spectre of instability in the tiny but strategically important Red Sea state.
Guelleh's Union for the Presidential Majority (UMP) declared victory in the election, claiming 49 out of the National Assembly's 65 seats.
The opposition rejected the vote as flawed and promised demonstrations.
International observers however reported no major incidents during the electoral process.
Guelleh has effectively presided over a one-party state since coming to power in 1999. The opposition accuses the 65-year-old leader of mounting oppression against Djibouti's 920,000-strong population.
Relatives of Abdourahim, a moderate Islamist who heads the Movement for Democracy and Freedom (MODEL) party, said he had been badly beaten during his detention.
In a radio broadcast, Interior Minister Hassan Darar appealed for calm, but made no reference to Abdourahim. Authorities have not confirmed his arrest. (Editing by Richard Lough and Jon Hemming)