KUALA LUMPUR, Malaysia (AP) _ The government arrested 23 people in a series of fires at government buildings in June, police said Wednesday.

The 23 are being held under the Internal Security Act, which enables the government to hold them without trial indefinitely, police said.

The men, all Malays ranging from age 25 to 62, were arrested between mid- October and mid-November. Authorities released their names but gave no indication as to their backgrounds or a possible motive for the fires.

However, the deputy president of the opposition Pan-Malaysian Islamic Party, Ustaz Fadil Nor, told reporters that at least two of those arrested were Moslem priests who were members of the party.

Jaffar Abdul, deputy inspector of police, said the men were arrested in connection with fires June 5 at the Kedah State Regional Development Authority and the District Government Office in Sik, 210 miles north of here in Kedah state adjoining the Thai border.

During the arrests, six revolvers, three hand grenades, a large quantity of ammunition of various types, several types of explosive devices were seized, Jaffar said.

Police are investigating what action should be taken against the men, including filing charges in court, he said.

In Malaysia all guns, ammunition, explosives and explosive devices have to be licensed. Anyone violating that law could be sentenced to death if charged and convicted under the Internal Security Act.

The act allows authorities to hold detainees withput trial for 60 days. The Home Affairs Minster can then sign an order holding them for a two-year period, to be followed by more indefinite detentions if necessary.

The group arrest announced Wednesday was the largest since 106 people were arrested under the act in October and November of last year. Since January they have been released in groups and now only 18 remain in jail, including parliament opposition leader Lim Kit Siang from the opposition Democratic Action Party.

Security officials say 80 people are being held under the Internal Security Act. When Mahathir Mohamad became prime minister in July 1981, 500 were being held.

The act is a remnant of British colonial rule and Malaysia, which won independence in 1957, has continued to use it for what it calls safeguarding national security.