The Department of Homeland Security announced Wednesday a sweeping crackdown on foreign nationals who legally enter the U.S. but remain after their visas expire, citing Sunday’s violent attack at a pro-Israel rally as the catalyst.

The attack has been attributed to Mohamed Soliman, an Egyptian national who overstayed his visa in 2022. In response, Homeland Security’s three immigration agencies pledged to intensify enforcement efforts by increasing immigration record checks and targeting visa overstays more aggressively.

“There is no room in the United States for the rest of the world’s terrorist sympathizers. Anyone who thinks they can come to America and advocate for antisemitic violence and terrorism — think again,” Homeland Security Secretary Kristi Noem said.

Soliman, who is facing state felony charges and federal hate crime allegations, was residing in the U.S. with his wife and five children at the time of the incident.

Court documents state that he shouted “Free Palestine!” while using a homemade flamethrower and firebombs to attack a demonstration calling for Hamas to release Israeli hostages.

While border crossings often dominate the immigration debate, visa overstays remain a significant concern. These individuals enter the U.S. on temporary visas—such as those for tourism, work, or study—but fail to leave once their visas expire.

Notably, several of the 9/11 terrorist hijackers were visa overstays.

According to the most recent Homeland Security report, an estimated 565,000 temporary visa holders overstayed their authorized stay in 2023.

While around 55,000 eventually departed by the end of the fiscal year, more than 500,000 remained in the country.

The overstay rate among student and exchange visa holders was nearly 4%, with some countries showing significantly higher figures. The government reported that over 70% of students from Equatorial Guinea, 54% from Eritrea, and 40% from Burma failed to return home by the end of 2023.

China’s overstay rate was lower at 1%, but that still accounted for more than 3,000 students.