MRT strategic communications and public relations director Amir Mahmood Razak said two sinkholes in Jalan Bukit Bintang were detected at an early stage, preventing them from becoming more serious.

“We deployed personnel every 20 metres to monitor the land surface area where tunnelling works were taking place beneath the roads,” he said.

He also said the sinkholes formed due to inconsistent pressure of limestone formation beneath the road.

“Limestone formations are not as hard as other geological formations as the former have air and water cavities, causing low earth pressure balance,” he said.

“We have reached the end of the 3.5km limestone stretch but we will conduct surface scanning to check if there are any more cavities underground before reopening the roads.”

Road modifications, bypassing the sinkholes, have been done to ease traffic flow in both directions.

Amir said the stretch was a transitional area between Kenny Hill formation and limestone formations, creating inconsistent pressure. A Kenny Hill formation is a typical sedimentary rock formation widely found within the Klang valley, which is an interbedding of sandstone, siltstone and shale.

Mayor Datuk Seri Ahmad Phesal Talib said the sinkholes were nothing to be worried about.

“The action taken to repair the problem was immediate and I hope that something can be done to shorten the repairing process,” he said when he visited the sinkhole site near Menara Worldwide yesterday.

He also said repair work was MRT’s responsibility and a third party would be brought in to conduct checks to ensure the safety of the nearby buildings.

The sinkhole formed in front of Menara Wordwide in Jalan Bukit Bintang at 9.35pm on Saturday.

Three underground water pipes were exposed and MRT alerted Syarikat Bekalan Air Selangor Sdn Bhd (Syabas), after which water supply was cut.

Water supply resumed at 11am yesterday after Syabas conducted checks.

The affected buildings were Menara LTAT, Menara Worldwide and Menara Yayasan Tun Razak.

Another sinkhole formed on Thursday night in front of Menara LTAT, from the merging of two road depressions that occurred on Wednesday and Thursday morning.