Police are tracking down two groups linked to several robbery cases on 24-hour convenient stores around Sentul here.

Sentul police chief ACP R. Munusamy said the first group comprising seven men and a woman were suspected of robbing KK Mart in Taman Kok Lian at 5.20 am last Friday.

"They beat up two workers using helmets, plastic chairs and four empty liquor bottles," he told a media conference at the Sentul police headquarters, Friday.

Earlier, one of them was said to be unhappy when he was accused of trying to steal some items at the shop by a security guard, Munusamy said.

"Dissatisfied, the suspect returned to the shop with seven friends... five of them beat up two workers while another suspect stole RM657 from the cash register," he said.

The second group comprising three men robbed a 7-Eleven store at 5th mile Jalan Ipoh armed with a piece of wood on Feb 16.

In the 4.50 am incident, they grabbed RM1,300 in cash and several cartons of cigarettes and food," said Munusamy.

"The group was believed to be involved in at least four robberies of convenient stores in Sentul," he added.

Munusamy said members of the public with information were requested to approach the nearest police station or contact the Sentul police operations room at 03-40482222.