BEIJING - China called for calm and restraint on Monday after Turkey accused Syria of shooting down one of its military reconnaissance jets in international airspace and summoned a NATO meeting to discuss a response.US Secretary of State Hillary Clinton called the attack "brazen and unacceptable" and said Washington would cooperate closely with Ankara to promote a transition in strife-torn Syria. "China has noted the relevant reports and is paying close attention to developments," Chinese Foreign Ministry spokesman Hong Lei told a daily news briefing."At present, the regional situation is extremely complicated and sensitive. We hope that the parties concerned will exercise calm and restraint and adhere to diplomatic channels to reach an appropriate solution, so it does not escalate further."Turkish Foreign Ministry Ahmet Davutoglu said the jet had been clearly marked as Turkish and dismissed Syria's assertion it had not identified the aircraft before opening fire.International efforts to halt the violence in Syria are deadlocked because Russia and China, which wield vetoes in the UN Security Council, have blocked tougher action against Syrian President Bashar Assad.They say the solution must come through political dialogue, an approach most of the Syrian opposition rejects.The United Nations says Syrian forces have killed 10,000 people in the crackdown on protest against Assad's rule that broke out in March last year, inspired by uprisings across the Arab world which have toppled four autocratic leaders.Assad's government says foreign-backed Islamist militants have killed at least 2,600 Syrian police and troops.