GRAND RAPIDS, Mich. (AP) _ Lawyers flooded Michigan's circuit courts with lawsuits just before tough new rules governing liability claims went into effect.

Courts statewide reported dramatic increases in filings of medical malpractice and personal injury lawsuits just before Oct. 1, the effective date of the state liability insurance reforms.

About 150 civil liability cases are filed daily in Wayne County Circuit Court in Detroit, but 803 were filed Sept. 30, said court clerk James Killeen.

''At 10 o'clock at night we still had 250 lawyers standing in line,'' he said Monday. ''We're still working evenings and weekends to get (the suits) all into the (computer) system.''

Killeen said 2,676 cases were processed during a five-day span that normally would have seen about 750 cases filed. An additional 1,500 to 2,000 cases during that period were stamped and received, but not processed and counted, he said.

''There will probably be a second and third wave of filings because most of these cases will have to be amended,'' he said. ''The lawyers were just trying to get them in.''

In June, the Legislature passed a seven-bill package aimed at curbing frivolous lawsuits and reducing spiraling liability insurance premiums paid by doctors, bar owners and others in high liability risk occupations. Most of the laws went into effect July 7, but procedural revisions were effective Oct. 1.

Those changes limit where suits can be filed, alter rules for jury instructions and toughen qualifications for expert witnesses, said Mike Karwoski of the State Bar of Michigan.

William Murphy, a lawyer and president of the 2,600-member Michigan Trial Lawyers Association, said the mass filings also resulted from rules that prohibit interest on damages before a jury award is made and prohibit plaintiffs from recovering amounts already covered by their insurers.

''There isn't any question this surge is the result of that legislative package,'' said lawyer Joel Boyden.

Lawyer Frederick Royce III said he normally files one civil liability suit a week, but filed 23 liability cases last week.

About 20 of those cases are in the negotiation stage with the defendants' insurance companies. He said he expects half of them to be settled before trial.

But Royce said he filed the cases before Oct. 1 so they wouldn't be covered by what he said were unfair restrictions on plaintiffs' rights.