The tremors, which lasted for several seconds, were accompanied by a loud booming sound, Sinar Harian reported.

Netizens on social media said that tremors were felt in areas such as Tasek, Meru, Falim and Manjoi, as well as by motorists on the North-South Expressway near the Menora Tunnel.

M Diviya, 30, reported that the tremors were so intense that the glass door of her office seemed about to shatter.

“I heard a booming sound like a bomb from above. My friend and I immediately left the office as we were worried it might collapse,” she was quoted as saying.

She added that she contacted the mineral and geoscience department to report the incident and was told that the department had received calls from several people who made similar complaints.

Some claimed that the tremor might have been caused by quarry activities.

In a statement, Perak police chief Azizi Mat Aris said police are currently investigating the incident after being informed about it at about 11am.

He said no explosives training was conducted at the northern brigade of the general operations force base in Ulu Kinta today.

Azizi said the meteorological department did not detect any seismic activities in the Ipoh district. However, a minor earthquake had been recorded in Halmahera, North Maluku province, near Sulawesi, Indonesia, at 11.24am at a depth of 11km beneath the seabed.

Meanwhile, Perak mineral and geoscience department director Nizarulikram Abdul Rahim confirmed with Bernama that the boom and tremors were not linked to any quarry activities.

“I can confidently say it wasn’t from quarry blasting. We’ve checked, and there were no authorised blasts today. Furthermore, quarry explosions are only permitted between noon and 5pm on weekdays.”

Nizarulikram also noted that this is the third such mysterious incident in Ipoh, with similar occurrences reported in June 2012 and October 2018 — all happening around 11am.