Kerry says raised rights concerns in talks with Bahrain minister

* Kerry met Bahraini counterpart in Saudi Arabia on Monday

* Gulf Arab state a vital strategic U.S. ally

* Reconciliation talks between govt and opposition on-going

DOHA, March 5 (Reuters) - U.S. Secretary of State John Kerry said on Tuesday he had voiced concerns about human rights in Bahrain with the foreign minister of the strategically vital Gulf Arab kingdom where protesters are demanding democratic reforms.

Home to the U.S. Fifth Fleet, the tiny state has been hit by unrest since pro-democracy protests in early 2011, becoming a front line in a region-wide tussle for influence between Shi'ite Muslim Iran and Sunni Arab states such as Saudi Arabia.

The mass disturbances were crushed but demonstrators, mainly from Bahrain's Shi'ite majority, have continued small protests on an almost daily basis demanding the Sunni ruling family call elections and create a constitutional monarchy.

Describing his meeting with Foreign Minister Sheikh Khalid Bin Ahmed al-Khalifa on Monday, Kerry told a news conference on a visit to neighbouring Qatar that he had encouraged Bahrain's government to continue talks with the opposition aimed solving their political differences.

"We had a good, constructive conversation. I expressed concern for the protection of the rights of everybody," said Kerry, who met Sheikh Khalid during a visit to Saudi Arabia.

Bahrain's mostly Shi'ite opposition and the Sunni Muslim-dominated government resumed reconciliation talks on Feb. 10 to try to agree on political reforms. But the talks - the first between Bahrain's opposition and government since July 2011 - have been clouded by violence.

One protester and a policeman died in clashes on the second anniversary of the start of the opposition protests last month.

According to the opposition, a second protester died in late February. The government said at the time it was investigating and that there was no evidence police were involved.

"The foreign minister made it clear to me that they remain committed to the dialogue, and they are engaged right now in advancing it," said Kerry, who is on his first overseas tour since his appointment.

"I encouraged him to continue that dialogue, and to reach a resolution. He assured me they would continue in good faith."

Some 35 people died during the 2011 unrest and in the two months of martial law afterwards, according to an independent commission of inquiry. The opposition says at least 80 died.

Bahrain has accused Iran of fuelling the unrest, an accusation Tehran denies.

In September, the then U.S. Assistant Secretary of State for Democracy, Human Rights and Labor Michael Posner urged Bahrain to reform its police and security forces, allow free trade unions and dismiss criminal charges against all who have taken part in peaceful political expression. (Reporting By Regan Doherty and Arshad Mohammed; Writing by William Maclean; Editing by Robin Pomeroy)