SINGAPORE - A sales executive was sentenced to a total of 25 weeks' jail on Wednesday (Feb 17) for attacking three people at popular nightspots.

Edwin Lek Yong Zen, 21, had admitted to three of six charges of voluntarily causing hurt - punching Mr Ng Zi Jing and Mr Joseph Louis Legaspi at Boat Quay on Nov 15, 2014, and punching Mr Winson Tan Ting Wei, 27, with an accomplice Su Peiji, 29, at Circular Road on April 18 last year .

A district court heard that Mr Ng and his friend, Mr Theorell Tang Qi Han, 21, went to Bubble Room at Boat Quay to have some drinks in the early hours of Nov 15, 2014.

When the pub was about to close at 3am, they left and went outside to smoke.

Lek approached Mr Tang and accused him of behaving in an annoying manner inside Bubble Room. He then punched Mr Tang on his lips once.

When Mr Ng intervened, he was attacked as well.

After Lek assaulted Mr Ng, Lek was restrained by his friend, Chia Yuan Jian, 22. The duo were joined by another friend and all three walked down Boat Quay towards North Bridge Road.

Investigations showed that American Legaspi, 40, an operational work representative for the US Naval Base in Singapore, and a fellow American, Mr Moran Jason Edward, 41, were walking along Boat Quay when they heard the commotion behind them. They turned and saw what had happened.

When the trio caught up with Mr Legaspi and Mr Edward, Chia suddenly head-butted Mr Edward in the chest. Chia then threw two punches at Mr Edward's face. Lek punched Mr Legaspi hard in the face, causing him to fall to a kneeling position on the ground.

Mr Legaspi was taken to hospital where he received stitches for a 1cm cut on his chin.

In the third incident, the court heard that Lek had a dispute with Mr Yeo Tiong Beng, 39, at Shebang Pub at Circular Road on April 18 last year. During a scuffle, both fell.

Mr Winson Tan came and stopped the scuffle.

Lek left the pub and called his sister who was nearby with her boyfriend, Su, 30, to tell them what had happened.

Lek's sister and Su went to Circular Road and there, she advised Lek to go home and he agreed.

While walking along the road, Lek saw Mr Tan standing outside the pub and became furious. He punched Mr Tan. The fight spilled into the pub, and Su joined in. Both men assaulted Mr Tan.

Chia has pleaded guilty, but his case has been adjourned to March 17. Su has been fined $1,000.

Lek could have been jailed for up to two years and fined up to $5,000 for each charge.