* Ministry says signs of explosive substances in car
* Bahrain hit by several small bombings in recent weeks
* U.S. ally has yet to quell unrest from Shi'ite population (Adds witness, separate incident)
MANAMA, April 19 (Reuters) - Two people were killed and one wounded when a car blew up in a mainly Shi'ite village in Bahrain on Saturday, and the interior ministry said there were signs the vehicle had been carrying explosives.
In a separate incident, the ministry said a homemade bomb wounded three civil defence officials as they were putting out burning tyres near the entrance to a village outside the capital, Manama.
Sunni-ruled Bahrain has been hit by several small bombings in recent weeks as the kingdom struggles to end simmering unrest among its Shi'ite Muslim majority, which rose up unsuccessfully in an Arab Spring-inspired revolt in 2011.
The small Gulf state is an ally of the United States, which bases its Fifth Fleet there and sees it as a bulwark against nearby Shi'ite Iran.
The interior ministry said on Twitter that the car incident took place in the village of al-Maqshaa', along the Budayya highway outside Manama.
"Initial inspections uncovered two burnt bodies and a third with burn wounds was taken to hospital," it said.
A witness who declined to be named said he had heard two explosions. One man managed to escape the car after the first blast. The second one killed the remaining two people in the car, the witness told Reuters.
Bahrain's Shi'ites want political reforms and an end to alleged discrimination against them, which the government denies. Many Shi'ite areas are still witnessing near daily clashes with police.
In one of the most serious recent attacks, three policemen were killed by a bomb in March while security forces were trying to disperse a group who were blocking roads in a village after a funeral.
Since then, several explosions, mostly of homemade bombs, have wounded at least three policemen in Shi'ite villages around the island. (Reporting by Farishta Saeed and a Reuters photographer; Writing by Yara Bayoumy; Editing by Mark Trevelyan)