Ukrainian troops tightened a security cordon around a major insurgent-held eastern city Tuesday, but

(6 May 2014) VOICE-OVER SCRIPT: (NATSOUND) THERE WAS PLENTY OF HEARTBREAK ON DISPLAY IN UKRAINE ON TUESDAY. (NATSOUND) NO SHORTAGE OF BICKERING. (NATSOUND) AND PLENTY OF TENSION. KIEV IS CONTINUING ITS CRACK DOWN ON PRO-RUSSIA MILITIA MEMBERS OPERATING IN EASTERN UKRAINE. ONE DAY AFTER FIGHTING LEFT DOZENS OF PEOPLE DEAD - MOSTLY PRO-RUSSIAN INSURGENTS --- UKRAINIAN TROOPS TIGHTENED A SECURITY CORDON AROUND THE RESTIVE CITY OF DONETSK. THE CITY'S AIRPORT WAS ALSO CLOSED TEMPORARILY. BUT DOZENS OF PRO-RUSSIA MILITIA MEMBERS SURROUNDED A UKRAINIAN BASE -- DEMANDING THAT TROOPS NOT JOIN THE GOVERNMENT'S ASSAULT AGAINST THE INSURGENTS. IN SLOVYANSK, PRO-RUSSIAN FORCES REINFORCED BARRICADES NEAR A BUILDING THEY ARE USING AS THEIR HEADQUARTERS. IN ODESSA -- IN SOUTHWEST UKRAINE -- WHERE A FAMILY MOURNED THE LOSS OF THEIR TEENAGER WHO WAS KILLED IN MAJOR VIOLENCE ON FRIDAY - UKRAINE TRIED TO REASSERT ITS CONTROL BY APPOINTING A NEW GOVERNOR. MEANWHILE -- THE U.S. IS DENOUNCING A PLANNED REFERENDUM THIS WEEKEND TO GIVE MORE AUTONOMY TO PORTIONS OF EASTERN UKRAINE. THE U.S. SAYS IS CALLING IT ILLEGAL --AND WON'T RECOGNIZE THE RESULTS. (NATSOUND - LAVROV IN VIENNA) RUSSIA IS BLAMING THE UNREST ON KIEV. AND TUESDAY, RUSSIAN FOREIGN MINISTER SERGEY LAVROV DEMANDED THE UKRAINIAN GOVERNMENT END ANY ATTACKS ON REBEL STRONGHOLDS. LAVROV SAID RUSSIA IS OPEN TO ANOTHER ROUND OF INTERNATIONAL TALKS TO EASE THE CRISIS -- BUT ONLY IF PRO-RUSSIA REBELS ARE ALLOWED TO ATTEND. KIEV IS REJECTING THE PROPOSAL. IT SAYS RUSSIA IS FOMENTING THE UNREST -- HOPING TO DERAIL UKRAINES PRESIDENTIAL ELECTION ON MAY 25TH. SIGOUT - NED BARKER/Associated Press Find out more about AP Archive: http://www.aparchive.com/HowWeWork Twitter:   / ap_archive   Facebook:   / aparchives   ​​ Instagram:   / apnews   You can license this story through AP Archive: http://www.aparchive.com/metadata/you...