Jakarta – Police on Wednesday defused a small bomb left in a shopping centre in the central Indonesian town of Balikpapan, which is home to several international oil and mining companies, an officer said.

The bomb, described as a low-explosive device, was discovered late on Tuesday by employees at Mall Fantasi in the town on Kalimantan island, 1,215km northeast of Jakarta, said police.

Bomb squad officers defused the device, which was concealed in a plastic bag, early on Wednesday. The mall had been given no warning.

Police declined to speculate on who planted the bomb, but said anonymous callers had phoned in bomb threats that turned out to be false to other businesses in the town in recent weeks.

Indonesia has been hit by a series of bombings in recent years. The major attacks, including the 2002 Bali blasts, have been blamed on Islamic militants.

Balikpapan is home to several international companies with oil and mining operations close to the town, and off the coast of Kalimantan, including ExxonMobil and British Petroleum.