Saudi Arabia has confirmed seven new cases of Middle East Respiratory Syndrome (Mers), adding up to 36 infections in five days, a sudden increase of a disease that kills about a third of the people infected and has no cure.

Mers, a SARS-like novel coronavirus that emerged in Saudi Arabia two years ago, has infected 231 people in the kingdom, of whom 76 have died, the Health Ministry said on its website.

Meanwhile, another cluster of cases has been detected in the United Arab Emirates, and a Malaysian who was recently in the Gulf has been confirmed as infected, his country said.

Mers has no vaccine or anti-viral treatment, but international and Saudi health authorities say the disease, which originated in camels, does not transmit easily between people and may simply die out. Health experts have warned, however, that Mers has the potential to mutate eventually.

The number of officially confirmed Saudi cases has jumped suddenly.

Saudi authorities last week reassured the public that there was no immediate cause for concern.