Small groups of migrants continued to sneak into Hungary on Wednesday, a day after the country sealed its border with Serbia and began arresting people trying to breach the razor-wire barrier, while a first group arrived in Croatia seeking another way into the European Union.

Hungarian prosecutors also said they put four Iraqis on trial for "the crime of crossing the border illegally," the first migrants to go to court under new laws that took effect Tuesday aimed at stopping the huge flow of migrants across the border.

While the tough new measures have mostly stopped the flow across the border, isolated groups still managed to crawl under or climb over the forbidding barbed wire of the 175-kilometer (110-miles) border fence to enter the European Union.

Early Wednesday, Associated Press reporters saw police on horseback surrounding a group of 14 Afghans, including five young girls and an elderly woman, in a field close to the fence.

As they watched over the group, the horseback police officers' radio crackled with news of other migrants being detained — one Syrian, one Afghan, a group of 11.

Driving along the fence early in the morning, there was evidence of how it has been breached, though it was not clear when it happened. In one spot there was evidence that migrants passed over the barrier, with a carpet still covering three rolls of razor wire.

Small groups of young men also walked along roads leading away from the border. One asked a passing reporter: "Is this the way to Budapest?"

On Tuesday, Hungarian police arrested at least 174 migrants for illegally breaching the border or damaging the fence.

With the border mostly sealed, though, thousands of migrants were stuck in Serbia, but others were seeking new paths on their way to Western Europe, some choosing to take the longer route through Croatia.

About 80 people crossed into Tovarnik, Croatia, early Wednesday after they were first bused to the Serbian border town of Sid, following an all-night ride from Macedonia.

Dozens of police and aid workers waited for the migrants across the border in Croatia, where they are being registered. Local media say some migrants have sought to cross into Croatia through nearby fields to avoid registration.

Officials say three more buses are expected to arrive in Sid later in the morning.

Migrants have avoided Croatia in the past because they must still go into Hungary or Slovenia before reaching Austria or Germany.

Meanwhile, Austria began selective controls of vehicles at three main border crossings with Hungary as it tries to impose some order over the stream of people.