SINGAPORE - Repair works are expected to be completed on Monday (Oct 30) night after a pipe burst in Upper Serangoon Road towards Sengkang and Hougang early the same morning, national water agency PUB said in an update on its Facebook page.

After the incident, all lanes were closed, before one lane was opened to motorists.

The roads have since been reopened to traffic, PUB said in its update around 8pm.

This is except for a 10m stretch of the first lane, near the junction of Upper Serangoon Road and Wolskel Road, that is still closed for repairs.

Traffic was smooth despite this, PUB said.

A statement posted at 11.38am said: "PUB received a report on a pipe leak at Upper Serangoon Road around 2am on Monday, and immediately sent our service crew and contractors to the site."

It explained that the leak was isolated at 8.45am, and that water supply to customers was not affected.

"Repairs are expected to complete by today," it added.

Bus operator SBS Transit also sent out tweets at around 6.20am informing commuters of bus service diversions in Upper Serangoon Road due to urgent road works.

The services affected were numbers 100, 107, 107M, 133, 135, 147 and 153.

It later tweeted that normal bus services had resumed at 7.51am.

When The Straits Times arrived at the scene at 7.25am, there were cracks visible on the road, with water streaming out of them.

Chiropractor Will Kalla, 41, who was about 150m from the affected junction, said: "I knew something was wrong because there were no cars on the road. All I could see in the distance was just water and police cars and some PUB staff."

He was waiting with his three-year-old daughter for her school bus to Marymount Kindergarten which usually arrives at 7.20am.

"We waited for 15 minutes, before my wife called the driver. He said he could not get to where we were. So we had to walk about 500m through the housing estate to get to Bartley Road where he was waiting."

Mr James Wee, 34, whose son attends a nearby kindergarten, said: "Usually I drop him off in the morning, but today I had to walk him here because it will take longer by car."

Mr Wee, who works in the IT industry, said that he lives nearby. "Luckily it's near enough that we can walk here."

Another driver was overheard saying that her son has to sit an examination in the morning.

A check on the Singapore Examinations and Assessment Board (SEAB) website showed that there were two O-level combined humanities written exams at 8am.

The Straits Times understands that the disruption will be handled by the Ministry of Education (MOE) similarly to any other transit related delay.

The SEAB website says parents of affected students should call the schools and keep them in the loop. Affected students will be given time allowance. They also have the option of going to a nearby examination centre to take the exam.

In a Facebook post at 7.57am, the Singapore Police Force told motorists to "avoid using the roads in the vicinity and to take alternative routes during the closure".

It added that motorists should tune in to the radio for the latest traffic updates.