Kuwait has stepped up security after a suicide bomber who flew in from Saudi Arabia blew himself up inside a Shiite mosque during Friday prayers, killing himself and 26 other people. Kuwaiti officials said the attack was aimed at stirring up sectarian strife in the country.

Security sources in the country as saying that 60 people, including Kuwaiti citizens and nationals of other Gulf states, were being held for investigation by security services.

They also said that five people suspected of involvement in Friday’s mosque bombing by Saudi national Fahd Sulaiman Abdul Mohsin Al Qaba’a had been referred to the public prosecutor. The five suspects had confessed to receiving financial transfers from abroad to carry out attacks targeting houses of worship.

The bombing has sharply heightened regional security concerns because Daesh (ISIS) appears to be making good on its threat to step up attacks in Ramadan.