MANILA – Tensions over competing claims in the South China Sea could escalate into conflict, with an arms build-up among rival nations raising the temperature, an international think tank warned Tuesday. Prospects of solving the disputes “seem to be diminishing" after a recent failure by the 10-nation ASEAN grouping to hammer out a “code of conduct" that would govern actions in the sea, the International Crisis Group (ICG) said. “Without a consensus on a resolution mechanism, tensions in the South China Sea can easily spill over into armed conflict," warned Paul Quinn-Judge, the ICG's program director for Asia. The Philippines Tuesday summoned the Chinese ambassador to protest against China's plans to establish a military garrison on the disputed Paracel Islands in the South China Sea. The foreign department said it summoned Ma Keqing to lodge the complaint, and also to object to the arrival of a military-escorted Chinese fishing fleet near the contested Spratly Islands. The Chinese Defense Ministry announced plans to operate troops from Chinese-held Sansha or Woody Island in the Paracels Monday, a month after Beijing designated the island as China's administrative center for both the Paracel and Spratly groups. China says it has formed a municipal council for the newly established city, and has authorized the deployment of a military base in the area. Beijing has created the city administration to oversee not only the rugged outpost but hundreds of thousands of square kilometers of water, aiming to strengthen its control over disputed — and potentially oil-rich — islands. A spokesman for the Philippines Foreign Ministry said Manila did not recognize the city or its jurisdiction. Vietnam said China's actions violated international law. While the Philippines does not have territorial claims on the Paracels, foreign department spokesman Raul Hernandez said the Chinese plan to administer both island groups from Sansha was unacceptable. – Agencies