Owners of new Honda CR-V sport-utility vehicles in the United States continue to report vehicle fires shortly after initial oil changes, and a federal agency reportedly is keeping an eye on the problem two months after closing an investigation.

According to the Washington Post, by the end of last week, 20 people had reported fires on 2004-model CR-Vs to the National Highway Traffic Safety Administration, and another five people had reported oil leaks and smoke. That was up from five reports in late June, shortly before the federal agency closed its investigation.

Honda Motor identified another 22 such fires in 2003-model CR-Vs during the government's inquiry. No injuries have been linked to the fires, but several of the reports detailed narrow escapes from vehicles that often were destroyed by flames, the report added.

Agency spokesman Rae Tyson told the paper NHTSA investigators are "aware of the new complaints that have come in, they've been in communication with Honda, and they are going to continue to monitor to see if Honda's efforts to communicate with the service departments has had the desired effect."

The company reportedly said the problem seems to stem from technicians, usually at dealerships, improperly replacing oil filters during the first oil change. The rubber gasket inside the rim of the car's factory-installed oil filter sometimes sticks to the engine block, and when a new filter is installed over it, the stacked gaskets fail to seal properly. Oil leaks out and sprays onto the car's hot manifold, catching fire.

What Honda hasn't been able to explain is why the 2003 and 2004 model CRVs would be especially prone to the problem, the Washington Post noted.

It said that, in mid-July, Honda sent letters to its dealerships pointing out the potential problem and urging them to take care in changing oil filters. The company also sent out notices on an internal e-mail system and posted the topic on a website for Honda owners.

Honda was unable to include a notice in a quarterly publication sent to independent service companies such as Pep Boys, a spokesman told the paper, because the publication went to press before the decision was made to address the problem. The next edition, out in October, will carry the notice.

Honda USA's spokesman reported said the company believes the information campaign is making a difference. Since the notices went out to dealers July 14, Honda counted nine new incidents, none in the past 20 days.

But the Washington Post said those numbers do not match complaints on file at NHTSA, which show two new incidents in the past two weeks and eight since July 14. But NHTSA does not provide enough information to correlate its complaints with those received at Honda, the spokesman reportedly said, so there's no way to know if they're tracking the same ones.

Still unanswered is the question of why the CR-V seems prone to catch fire from a simple oil leak, the Washington Post said. Honda's spokesman told the paper the company is still investigating, but that there has been no change in filters or engine design that would readily explain the problem.

David Champion, chief auto tester for Consumer Reports, told the Washington Post he and his staff have looked at the CR-Vs and come to no firm conclusion about the cause. It's possible, Champion said, that Honda has changed the type of paint or coating it uses on the engine block, causing the oil filter gasket to stick after being installed at the factory. But the spokesman said Honda does not believe that to be the case.

He reportedly added that Honda is supporting its dealers with information, but that it believes the problem lies with technicians who do not follow proper oil-changing procedure. In cases where a burned CR-V has had to be replaced, the spokesman said, it's been up to individual dealerships and their insurance companies to foot the bill.