MALANG, Indonesia—A strong earthquake killed at least seven people, injured 12 others and damaged more than 300 buildings on Indonesia’s main island of Java and shook the tourist hotspot of Bali, officials said Saturday. No tsunami warnings were posted. The U.S. Geological Survey said the magnitude 6.0 quake struck off the island’s southern coast at 2:00 p.m. local time (0700 GMT). It was centered 45 kilometers (28 miles) south of Sumberpucung town of Malang District in East Java province, at a depth of 82 kilometers (51 miles). Rahmat Triyono, the head of Indonesia’s earthquake and tsunami center, said in a statement the undersea tremblor did not have the potential to cause a tsunami. Still, he urged people to stay away from slopes of soil or rocks that have the potential for landslides. This was the second deadly disaster to hit Indonesia this week, after a severe downpour on Sunday triggered …