More than 100 subpoenas were issued by a grand jury this week in a state probe of possible corruption in the government of St. Mary's County, Md., state prosecutor Stephen Montanerelli said today.

Montanerelli said the subpoenas follow a long probe into the county government, and he confirmed that the county's practices for issuing industrial revenue bonds were being investigated.

It could not be determined who was subpoenaed or what transactions were being investigated.

St. Mary's County, home of the Patuxent Naval Air Test Center, has enjoyed a building and development boom in recent years and has attracted large numbers of firms working in high-technology fields.

Apart from the current investigation, planning, zoning and development decisions of the county government had been the subject of controversy. Some county residents have criticized development decisions because three of the county's five commissioners and the county administrator are involved in real estate development or sales, and the chairman of the county's planning board is a banker involved in real estate financing.

Montanerelli said the investigation is far from finished and he does not expect indictments soon. Despite the large number of subpoenas, he said, "it's not a fishing expedition. We are looking at specific things."