BEIRUT (Reuters) - Twenty-eight people have been charged with planning to carry out suicide bomb attacks and belonging to the militant group Islamic State, Lebanon's state news agency said on Monday.

The move follows three bombings in Lebanon late last month and a security crackdown in the capital Beirut and other parts of the country.

Lebanon has suffered a wave of sectarian violence linked to the conflicts in Syria and Iraq, which are fighting insurgencies and have lost control of large tracts of land to Islamic State, a powerful jihadi militant group straddling the border.

Seven of the 28 charged by prosecutors on Monday are in custody, the agency said. The prosecutor at the military court charged the group with buying equipment to carry out attacks in residential areas of Beirut and for supplying it to potential bombers.

The case has now been referred to a military magistrate, the agency added. It did not give the names or nationalities of those charged.

Lebanese authorities have carried out a series of security raids on hotels in the capital and other parts of the country in recent weeks after the latest series of attacks.

The head of Lebanon's General Security service narrowly escaped a suicide bombing near the Syrian border on June 20. Three days later, an attacker blew up his car near an army checkpoint in Beirut, killing himself and a security officer.

A Saudi suicide bomber wounded three security officers in a hotel close to the Saudi Arabian embassy in the capital two days later. Shortly before that bombing, security forces detained 17 people at a Beirut hotel on suspicion of planning attacks.

France's foreign ministry confirmed on June 24 that one of the men detained in the hotel raid had French nationality. Lebanese security sources said a French man of Comorian origin was the only one of the original 17 who was still in detention a day later and that the others were released.

(Reporting by Sylvia Westall; Editing by Ralph Boulton)