The death toll continued to mount Tuesday, with Indonesian leaders saying up to 2,000 people may have perished after a 8.7-magnitude earthquake off the coast of Sumatra renewed fears of another tsunami disaster throughout Indian Ocean coastal regions. Vice President Jusuf Kalla said the estimate of those killed in the quake could be in the thousands, but due to poor communication it was still difficult to get an accurate assessment of the damage in affected areas. "This is just a rough estimate that between 1,000 to 2,000 people were killed in the earthquake," Jusuf Kalla told reporters. Most of the deaths came on the island of Nias, some 1,500 kilometers northwest of Jakarta that was closest to the epicenter. But new reports said 100 people had been killed on the island of Simeulue and 2,000 others were injured. The total inhabitants on the island were 70,000. Aid workers in Medan, a major city nearby that has become a regional hub for aid distribution following the December 26 earthquake-triggered tsunami, were scrambling to get to the island of Nias and other areas nearby. The airport tower on Nias had collapsed and the runway was cracked, making it impossible for relief planes to land, forcing aid workers to travel overland, a journey they said could take a full day by vehicle and boat. In the meantime, aid workers were collecting information on the damage through networks of volunteers and workers on the island. --more 1259 Local Time 0959 GMT