An explosion and a gun battle killed five people in a southern Kazakh city on Saturday, following a threat by Islamist militants to carry out attacks in the oil-producing state that was long seen as the most peaceful in Central Asia. A recent series of blasts and shootouts, including one claimed by Islamist militants, has unnerved the authorities and public of the former Soviet republic, a mainly Muslim nation of nearly 17 million. A local resident of the city of Taraz told Reuters that he heard the sound the of explosions and gunfire in the center of the city, about 550 km (350 miles) west of Almaty, Kazakhstan's financial center and biggest city. "We never thought that this kind of thing could happen here," said the resident, who did not want to be identified. He said many people had been wounded and that the city center had been cordoned off.