A firebomb attack was launched at a bar in San Luis Rio Colorado, Mexico which borders the United States, killing 11 people on Friday night.

BBC reported that a man has been arrested in Mexico on suspicion of the attack, by setting the bar on fire after he was kicked out.

Authorities revealed that a drunk young man hurled a Molotov cocktail at the Beer House bar after being thrown out following a report that had been harassing women.

The mayor of San Luis Rio Colorado tweeted on Saturday afternoon that a suspect had been arrested, but did not reveal the identity.

The fire killed seven men and four women and left four other people hospitalised, according to a statement from the Sonora state Attorney General’s Office.

A number of those injured were rushed across the border to hospitals in the US for treatment, BBC said.

“According to versions (from) several witnesses, the person with a young, male appearance was disrespecting women in that bar and was expelled,” the statement said.

It described the object thrown as “a kind of ‘Molotov’ cocktail”.

Investigations have continued to “clarify the facts” and “bring justice” it said, adding that “in Sonora, no one is above the law”.

It was unclear if the incident was related to organised crime, which has plagued Mexico for years.