Police and the army battled al-Qaida militants in a western Algeria town, killing two extremists in a fierce gun battle, residents and local media said Sunday. The clash took place overnight Friday in the border town of Maghnia, near Morocco. It came as authorities bolstered security throughout western Algeria in anticipation of an important OPEC conference this week in Oran, a coastal city 150 kilometers from Maghnia. Ministers from the 14 members of the Organization of Petroleum Exporting Countries, as well as Russia's deputy prime minister and several other officials, are scheduled to arrive by Tuesday. Local media reported that police negotiated with the terrorists for six hours before an elite army squad stormed the house in the impoverished Matmar neighborhood, firing assault weapons and exchanging grenade blasts with the two militants.