JAKARTA (Reuters) - Three bystanders were killed and a small child was wounded when separatist fighters in Indonesia’s Papua province opened fire on a small plane bringing in security personnel ahead of regional elections due later this week, officials said on Monday.

Voting will take place across Indonesia on Wednesday but security personnel are on high alert in Papua, where a long-running independence struggle has often turned violent.

A group of armed men ambushed and shot at the plane after it landed at the tiny airport and also at vendors near the airstrip, a military official said.

“The plane was carrying 15 mobile brigade officers tasked with safeguarding the local election,” said Muhammad Aidi, a military official of Nduga regency. He said the pilot suffered a slight wound.

Indonesia took control of Papua following a widely criticized U.N.-backed referendum in 1969, six years after the end of Dutch colonial rule.