There was a spike in fatal Rhode Island roadway crashes in late spring as the state emerged from two months of tight COVID-19 restrictions, although officials say they don’t know for certain if there is a relationship between the crashes and reopening.

Ten people died in crashes in both May and June, more than any single month in more than two years, according to preliminary figures in the state Department of Transportation’s most recent quarterly report. The previous high monthly death toll was eight deaths in September 2018.

In January, before COVID-19 arrived, there were four traffic fatalities in Rhode Island. The monthly total fell to two in February, five in March and three in April before the spike in May.

“It takes some time to receive toxicology reports and for crash investigations to be completed, but from this process, we do learn the causes and contributing factors in these crashes, such as impaired driving, distracted driving and speeding,” Department of Transportation spokesman Charles St. Martin wrote in an email. “However at this time we don’t know if there is any connection between changes in traffic volumes during the pandemic and the fatalities we’ve seen this year.”

Since the end of June, the number of roadway deaths has gone back to average levels. There were five traffic fatalities in July and six in August, St. Martin said, noting that the numbers are preliminary and subject to revision.

Going back to 2013, May has the highest average fatality rate of any month, with an average of seven deaths.

Although it doesn’t mention the COVID lockdown directly, DOT’s quarterly report points to a connection between emptier highways, speeding and more lethal crashes.

“Consistent with the national trend, Rhode Island is experiencing an uptick in fatalities,” the quarterly report says. “While the overall rate of crashes has reduced due to less cars on the road, cars are speeding, and when a crash occurs [at high speed] the fatality risk has increased greatly.”

Of the 45 traffic deaths so far this year (including the July and August) 11 of were motorcycle riders, 10 were pedestrians and two were bicyclists.