The violence began about 10 a.m. when an explosives-laden car parked in a garage blew up, local police said. Another car about 50 meters (yards) away exploded shortly afterward as people gathered to examine the damage from the first.
The third blast occurred across the street from a movie theater, also about 50 meters (yards) away, on Dijla Street, a major commercial road in the city center, police said, adding there were many casualties but the number could not immediately be determined.
Amarah, a Shiite militia stronghold about 320 kilometers (200 miles) southeast of Baghdad, is the provincial capital of Maysan province, which borders Iran. Iraqi forces took over control of security from British troops there in April.
The head of the British army, Nick Carter, said that Moscow was capable of taking "hostile actions" against the United Kingdom and NATO much earlier than expected