ZAGREB, Yugoslavia -- Federal army tanks battered Croatia's easternmost garrisons with shellfire, and warplanes struck its Adriatic coastline yesterday as the army launched the civil war's broadest and harshest assault against the secessionist republic.
Croatian officials appealed to Yugoslav military leaders in Belgrade twice for a truce in a conflict that is threatening to escalate beyond control, but there was no public response, suggesting that the federal authorities are bent on expanding territorial control in a weakened Croatia.
By midevening, scattered gunfire rippled through the suburbs of Zagreb, the capital of Croatia, close to a surrounded federal army barracks, indicating that the second offer of peace had made little headway.
After a week of humiliating Croatian blockades of federal army barracks in the republic, the federal army has apparently decided that this is the moment for a major push on several
fronts before its ability to deploy is overtaken by difficulties in finding new conscripts, uncertain morale and potential shortages fuel.
Witnesses along the Adriatic coast said warplanes and artillery pounded Sibenik and Split. A frantic radio broadcast from Radio Split to the outside world said: "We are without water and any lights. Our ports, roads, airports are closed off. Call your ministries. Stop the war in Croatia."
Since Croatia declared independence from Yugoslavia in late June, the army and Serbian militias that share the central government's opposition to the independence declaration have engaged Croatian forces in bitter fighting. There were no casualty reports from the fighting yesterday, but more than 500 people have died in the battles since June.
There were reports from witnesses yesterday that the federal army and Serbian militia forces had forced outgunned Croatian militias to retreat from a psychologically important bridgehead at Petrinja, 30 miles south of Zagreb.
Near Petrinja, Croatian militiamen watched as a black cloud of smoke hung in a sultry sky as artillery rocked positions in the town and their colleagues fell back over the bridge, threatening to blow it up to halt an army advance along the largely unguarded road to Zagreb.
"They have tanks and airplanes," said a guardsman, wearing the rosary beads of the Roman Catholic Church on his camouflage tunic. "We have hearts and will."
The Croatian defense minister, Gojko Susak, said 120 federal army tanks had been deployed and 120 more were on the Serbian-Croatian border as the federal authorities, backing Serb militias in areas of Croatia that are home to a large Serb minority, pressed to relieve beleaguered federal army garrisons in the eastern Croatian towns of Osijek, Vinkovci and Vukovar and to encircle Croat fighters there.
"They have thrown their best at us and we are holding them," he told reporters here after detailing an offer, sent to the Yugoslav Defense Ministry yesterday afternoon, to partially lift Croatia's blockade of federal army garrisons on its soil in return for a halt on "all offensive movements on the territory of Croatia."
The Croatian appeal to Belgrade's military authorities was sent to the Yugoslav defense minister, Veljko Kadijevic, and signed by Croatia's president, Franjo Tudjman, after an emergency meeting of his government yesterday. The message included a pledge to permit supplies of food, medicines, electricity and water to the beleaguered army barracks on Croatian soil, but not to fully lift the blockade, in return for a truce leading to negotiations on mutual matters and a disengagement.
The Croatian message -- sent to Belgrade by fax via the neighboring republic of Bosnia and Herzegovina because there are no direct communications between Zagreb and Belgrade -- suggested that both sides urge their forces to heed the new cease-fire terms by 7 p.m. local time with a view to halting the fighting.
But by nightfall, there was no indication that any appeal had been made by either side. An earlier truce under the auspices of the European Community came and went Wednesday with no halt to the war.