UPDATE 7-Rebel soldiers say they have seized power in Mali
* Whereabouts of President Toure unknown
* Regional body Ecowas condemns junta
* Hospital admits 20 with bullet wounds, no dead reported
* U.S. says backs Toure (Adds Ecowas, curfew)
By David Lewis and Tiemoko Diallo
BAMAKO, March 22 (Reuters) - Mutinous soldiers said they seized power in Mali on Thursday and ordered its borders closed, threatening to reignite conflict in a Saharan region shaken by the turmoil in Libya.
The overnight coup bid was led by low-ranking soldiers angry at the government's failure to stamp out a two-month-old separatist rebellion in the north of the west African state.
Heavy weapons fire rang out throughout the night as the presidential palace came under attack. The whereabouts of President Amadou Toumani Toure, who oversaw a decade of relative stability, are unknown.
Mali's neighbours, the United Nations and world powers from Paris to Washington called for a return to constitutional rule, while regional decision-making body ECOWAS Commission said it would not recognise the junta. Continued...