BRAZZAVILLE -- Voting got off to a slow start in Congo's parliamentary election on Sunday, after a campaign marked by a clear desire on all sides to revive the economy and fractured society of the war-torn Central African country.

Ballot booths opened at 6:00 am (0500 GMT) but an hour later many in the capital were still not operational because election officials were sorting out the voting slips.

Voting by Congo's 1.72 million electors was due to end at 6:00 pm (1700 GMT) but could be extended by the Interior Ministry to compensate for the late start, AFP reported.

More than 1,200 candidates are vying for 137 parliamentary seats in Sunday's first-round ballot. More than half the candidates are young men and women aged between 25 and 45.

A second round of voting for the five-year mandates will take place on June 23 at the same time as municipal elections.

The ballot has been postponed in eight of the 14 voting districts in the southern region of pool, where government troops have been fighting "Ninja" rebel militia since March 29, causing thousands of locals to flee.

In another sign of the prevailing insecurity, the Interior Ministry banned all road, rail and air traffic throughout Sunday's vote. Markets, shops and bars were to remain closed.

The elections follow a referendum in January approving changes to the constitution of the troubled oil-rich country, which has seen nearly a dozen coups and military uprisings since independence from France in 1960 and a decade-long series of civil wars that were only stifled last year.

Since the start of the campaign on May 10, most candidates have avoided mentioning the austerity measures the International Monetary Fund (IMF) and World Bank say are needed, in order not to shock an electorate crippled by unemployment.

More than half the country's youth, which makes up two thirds of the three million population, are without work.

Some 70 percent of people live below the poverty line, according to official figures.

Candidates have opted instead for vague promises ranging from building roads, schools and health centers to creating jobs -- but without saying how such schemes would be financed.

The United Democratic Forces (FDU) -- a group of parties close to President Denis Sassou Nguesso -- have kept their campaign in line with the president's program.

Sassou Nguesso, a former military ruler who seized back power in a 1997 civil war, was overwhelmingly elected in a presidential vote in March because the main opposition candidates either pulled out of the race, citing electoral fraud, or were prevented from standing.

His program focuses on the reconciliation process, reinforcing democracy, transparency in public affairs and the negotiation of a series of reforms with international financial institutions.

Among opposition candidates, the debate on economic matters has focused on good governance.

The main opposition coalition, the Convention for Democracy and Salvation (CODESA) is fielding candidates.

But two other opposition parties, which formerly backed a president and prime minister ousted by Sassou Nguesso, have split on the issue of staging a boycott. Some candidates have decided to stand, others will not.