Malaysia has declared high alert after Indonesian police claimed to have foiled a plot by IS-linked terrorists to set off bombs in Jakarta during the New Year celebrations.

“We are on alert. We are closely monitoring the situation,” Inspector-General of Police Khalid Abu Bakar said.

He was commenting on the arrests of five members of an alleged extremist network in Indonesia and seizure of chemicals, laboratory equipment and a flag inspired by the Islamic State group.

“Police personnel nationwide are on constant vigilance,” said Khalid.

Those arrested included a 31-year-old teacher at an Islamic boarding school in Central Java and his 35-year-old pupil.