KUALA LUMPUR - Malaysian authorities on Thursday arrested the chief executive and other senior managers of an Islamic conglomerate accused of running charity homes where children were allegedly sexually abused, amid a widening police dragnet in the case.

Nasiruddin Mohd Ali, the head of Global Ikhwan Services and Business (GISB) Holdings which police say is linked to a banned religious sect, was detained along with 18 people in an early morning raid on four residential premises in Kuala Lumpur, the Inspector-General of Police Razarudin Husain told Reuters.

Five other people linked to the company were also detained at the border with Thailand, Razarudin said.

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A GISB representative did not immediately respond to a request for comment. Nasiruddin and his lawyer were not immediately available.

Local media had earlier reported the arrests.

GISB's Nasiruddin on Saturday had denied allegations of widespread abuse at the youth care homes and other misconduct, though he acknowledged that "one or two" cases of sodomy occurred.

Police last week rescued more than 400 children and youths from the homes they said were run by GISB, though the firm has denied managing the shelters. Many of those rescued showed signs of neglect, as well as physical and sexual abuse, officials say.

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Razarudin said the people detained on Thursday included Nasiruddin's two wives, his children, as well as several children of late Malaysian preacher Ashaari Mohamed, the founder of the Al-Arqam religious sect which was outlawed by the government in 1994 for allegedly spreading deviant Islamic teachings in the Muslim-majority country.

Three men detained as part of the police investigation into GISB were also separately charged in court on Thursday, Razarudin said.

The men, who pleaded not guilty, face several charges of allegedly sexual assaulting boys at a religious school in Negeri Sembilan state, court charge sheets seen by Reuters showed.

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Each charge carries a maximum penalty of 20 years in prison, caning, or both.

Police previously charged two other people as part of its probe into GISB, which has businesses in over 20 countries ranging from mini-marts to restaurants and travel services. The firm is also under investigation for money laundering, religious offenses and other crimes.