Prominent Bahraini opposition leader Hassan Mushaima has returned from self-imposed exile to the UK, greeted by a crowd of supporters at the airport.
Mr Mushaima, a senior Shia figure, returned after the Bahraini government dropped charges against him, a move to appease protesters demanding changes.
In another concession, the king sacked four government ministers.
Meanwhile, thousands of demonstrators marched in the capital, Manama, as protests continue for a 13th day.
Mr Mushaima is known for his strong opposition to the ruling Sunni dynasty, and was sentenced in absentia last year on charges of trying to overthrow the government.
He was welcomed by supporters at the airport, where he told the BBC that he wanted genuine democratic reform that could turn Bahrain into a constitutional monarchy.
"We want a real constitution. They've promised us (one) before and then did whatever they wanted to," Mr Mushaima told reporters at the airport. BBC News
