Thousands protest Niger president's grip on power

NIAMEY (Reuters) - More than 10,000 anti-government protesters gathered in Niger's capital on Sunday calling on President Mamadou Tandja to reverse a constitutional rejig that gave him broader and extended powers.

Riot police were present but there were no clashes, witnesses said.

Heightened tensions in the uranium-rich central African country come amid stalled negotiations between Tandja's government and regional bloc ECOWAS, which canceled the country's membership last year.

Tandja drew widespread criticism and international sanctions after dissolving parliament and orchestrating a constitutional reform that gave him added powers and extended his term beyond his second five-year mandate, which expired in December.

"We hold Tandja responsible for the stalemate in negotiations initiated by ECOWAS and we believe his attitude is dangerous for our country," said Mahamane Hamissou, a member of the CFDR opposition group, speaking to the rally. "I am appealing to all Niger citizens to mobilize."

Despite political turmoil and occasional Tuareg rebellions, Niger has attracted billions of dollars in investments from major international firms seeking to tap its vast mineral wealth, including France's Areva and Canada's Cameco.

(Reporting by Abdoulaye Massalatchi; Writing by Richard Valdmanis; Editing by Louise Ireland)