The company Chipotle Mexican Grill saw a drop in its shares Wednesday after a few customers complained of stomach-related illnesses after dining out at a Chipotle restaurant in Pico Boulevard, Los Angeles recently.

The price of the shares was holding steady throughout yesterday till news of the illnesses surfaced online in the afternoon, causing it take a nosedive. Almost immediately there was a three percent drop in the share price and it ultimately closed as at a negative 4.63 percent at $298.67, according to New York Stock Exchange.

However, in after-hours trade, Chipotle shares showed an increase of 0.12 percent.

Five people took to the public health forum  IWasPoisoned.Com to complain of experiencing symptoms such as vomiting, diarrhea, and nausea after eating in the restaurant around Dec. 13.

"My whole family and I ate at Chipotle two days before we started experiencing stomach pains and nausea," one person wrote. "It was constant vomiting every two hours and weakness. We all had burrito bowls of meat, beans, rice, and guac. The symptoms lasted for two days now. We're starting to feel better, but it was a very uncomfortable experience and we won't be going to Chipotle anymore after this."

Similarly, another person wrote: “Ate there Wednesday and symptoms started late the next day with nausea, stomach distress, diarrhea, and vomiting. I only linked it because a co-worker is having the same symptoms and that is what we had in common.”

This is not the first time that Chipotle has had to deal with reports of their products making people sick. In July, the brand was forced to close down one of their restaurants in Virginia after similar reports of illnesses from a number of customers. At the time, Chipotle’s shares dropped seven percent.

On further investigation, it was found that there was an outbreak of norovirus at the Virginia facility which caused some of the people who ate there to fall sick. However, it is yet to be confirmed by health officials whether the LA restaurant has been plagued by the same virus.

Acute Communicable Disease Control unit of the Los Angeles Department of Public Health told CNBC: "Public Health routinely monitors and investigates reports of foodborne illness and communicable diseases in response to health concerns."

"We take any report of illness very seriously," Chipotle spokesman Chris Arnold told Business Insider. "We are aware of three reports (two of which appear to be the same) on a user-generated reporting site but there is no clinical validation associated with those reports, and we have not been contacted by customers directly to substantiate these claims.

“As a precautionary measure, we have implemented heightened sanitization measures at this restaurant, which we do as a matter of policy if ever we receive reports of illness (even if they are not substantiated),” Arnold added.

The spokesperson has denied the fact that reports of any viral outbreak in their LA facility have been made to the health officials. Instead, he drew attention to the fact that the Centers for Disease Control had reported a widespread case of influenza in California which was also keeping several of their employees from work.

"So all of this is happening against a backdrop of widespread illness throughout the state," Arnold said. Chipotle restaurants also saw an outbreak of E.coli a couple of years ago which sparked food safety concern among fast-food lovers.