The transport ministry will audit about 200 chartered bus operators nationwide in relation to overworked drivers and other possible breaches after a weekend bus accident in Gunma Prefecture that killed seven passengers, ministry officials said Wednesday.

The Japan Tourism Agency, an arm of the Land, Infrastructure, Transport and Tourism Ministry, also plans to conduct on-the-spot inspections of about 50 travel companies that consign bus tours to such operators.

The decisions precede plans by the ministry to set up an expert panel this month to review regulations covering tour bus operations, including the duration and distance for continuous driving, the officials said.