Actress and human rights activist Angelina Jolie made a visit to Lebanon to meet with Syrian refugees, the Associated Press reported.

Officials announced her surprise three-day trip on Monday. She traveled to the eastern Bekaa Valley, where at least 3,500 poor Syrian refugees now live, as the United Nations Refugee Agency Special Envoy. 

In total, the United Nations estimates that 2.5 million Syrians have become refugees and nearly 4.2 million are displaced following the uprising in 2011.

"Meeting these children was a heart-rending experience," Jolie said in a statement issued by the U.N. "They have lost their families and their childhood has been hijacked by war. They are so young, yet they are bearing the burdens of their reality as if they are adults." 

Lebanon, a tiny country neighboring Syria, has taken in at least 1 million refugees. According to the AP, the influx of refugees has raised rent prices, damaged infrastructure, and clogged their public health and education systems. The poorest residents have reportedly made tents out of billboard advertisements. 

"The generosity and solidarity shown by Lebanon and Lebanese to its neighbor serves as an example to the world for which we should all be grateful. We all need to help them bear this burden," Jolie said. 

According to activists in Syria, a military aircraft carried out a strike in Damascus on Monday.

Activist Mamoun Abu Saker said three different strikes hit homes killing at least four people, with others buried underneath the rubble. The Syrian Observatory for Human Rights confirmed the strikes but not the death toll.