In January 1992, the Sarajevo Agreement was signed by representatives of Croatia, the JNA and the UN, and fighting between the two sides was paused. After a series of unsuccessful ceasefires, the United Nations Protection Force (UNPROFOR) was deployed to Croatia to supervise and maintain the agreement. A stalemate developed as the conflict evolved into static trench warfare, and the JNA soon retreated from Croatia into Bosnia and Herzegovina, where a new conflict was anticipated. Serbia continued to support the RSK, but a series of HV advances restored small areas to Croatian control as the siege of Dubrovnik was lifted, and Operation Maslenica resulted in minor tactical gains. In response to the HV successes, the RSK intermittently attacked a number of Croatian towns and villages with artillery and missiles.