PORTLAND — A man and a woman who were found lying in a city street early Monday morning became the first people charged under Portland’s new graffiti ordinance.

Police arrested Robert Sinnott, 26, of Portland and Alana Saleeby, 22, of Scarborough on charges of criminal mischief and summoned each to court under the city’s graffiti ordinance, which was voted into law by the City Council on June 20.

The ordinance makes it against the law to apply graffiti or carry graffiti implements — the spray cans and markers used by people who “tag” public or private property.

Police say an officer saw Sinnott and Saleeby lying in the road near the intersection of Deering and Mellen streets at 1:40 a.m.

It’s not clear exactly where in the road the two were lying, or why, according to the police report, but as the officer checked on them, a resident of the neighborhood was calling police to report the graffiti.

A man who had been walking his dog a few minutes earlier had been drawn to where two people were applying graffiti by the sound of them whistling back and forth to each other, said Lt. Gary Rogers.

Police found graffiti, including heart symbols and “I love you” messages in lavender, inked on two street signs and two mailboxes.

Sinnott and Saleeby were charged with criminal mischief, a misdemeanor, and taken to the Cumberland County Jail. Each was issued a summons for allegedly applying graffiti.

Sinnott also was charged with possession of graffiti implements, after officers found a large marker that matched the ink of the graffiti, which was still tacky.

Under the ordinance, anyone who puts graffiti on public or private property can be fined $500 and required to do at least 25 hours of community service. Possession or furnishing of graffiti instruments subjects an offender to a fine of as much as $250.

The graffiti violation is a less serious charge than criminal mischief but still useful, said Trish McAllister, the city’s neighborhood prosecutor. Penalties for community service help city officials get the graffiti cleaned up.

Also, rather than having to prove beyond a reasonable doubt that someone committed a crime, authorities must prove the civil graffiti infraction by a preponderance of the evidence.

The city is taking a hard line on graffiti to keep it from getting out of hand, McAllister said.

“The … proliferation of graffiti in the city has been dramatic in the past five years or so,” she said. “We might not look like New York now, but if we don’t stop it, we will.”

Sinnott and Saleeby are free on bail pending an initial court appearance.