May 2000 With Eritrea's refusal to accept the US/Rwanda peace plan, on 22 February 1999, Ethiopia launched a massive military offensive to recapture Badme. Tension had been high since 6 February 1999, when Ethiopia claimed that Eritrea had violated the moratorium on air raids by bombing Adigrat, a claim it later withdrew. Surveying the extensive trenches the Eritreans had constructed, Ethiopian General Samora Yunis observed, "The Eritreans are good at digging trenches and we are good at converting trenches into graves. They, too, know this. We know each other very well". Ethiopia's offensive, codenamed Operation Sunset, began with an air attack on Assab airport by four Ethiopian fighter jets, followed by a massive artillery barrage against Eritrean positions on the Tsorona front, which was meant as a diversion to make the Eritreans prepare for an Ethiopian offensive against eastern or southern Eritrea. The following day, the Ethiopian ground attack began. Three Ethiopian divisions broke through the Eritrean defenses in the Biyukundi area and then advanced toward Dukambiya, 20 kilometers southeast of Barentu, before turning east and hitting an Eritrean division north of Badme in the flank, taking the Eritreans by surprise. The Eritrean division was almost totally destroyed and the Ethiopians continued their advance toward Dukambiya. Realizing that they were about to be cut off, the remaining Eritrean units deployed in the Badme area hastily retreated, abandoning nearly 100 kilometers of fortifications and most of their heavy weapons. Ethiopian helicopter gunships attacked the fleeing Eritreans with rockets. After five days of heavy fighting, Ethiopian forces were 10 kilometers (six miles) deep into Eritrean territory. Eritrea accepted the OAU peace plan on 27 February 1999. While both states said that they accepted the OAU peace plan, Ethiopia did not immediately stop its advance, because it demanded that peace talks be contingent on an Eritrean withdrawal from territory occupied since the first outbreak of fighting. The widespread use of trench warfare by both sides resulted in comparisons of the conflict to the trench warfare of World War I. According to some reports, trench warfare led to the loss of "thousands of young lives in human-wave assaults on Eritrea's positions". On 16 May, the BBC reported that, after a lull of two weeks, the Ethiopians had attacked at Velessa on the Tsorona front-line, south of Eritrea's capital Asmara and that after two days of heavy fighting, the Eritreans had beaten back the attack,