The Lebanese army said on Thursday one person was killed and two wounded during a search for suspected militants at refugee camps near the border with Syria.
Soldiers shot at three people on a motorbike who were trying to set fire to parts of a refugee camp during the raids, killing one and wounding the other two, it said.
After dark, the army fired artillery at suspected militants who tried to infiltrate from the border zone, apparently setting off land mines as they did so, a security source said. There were an unknown number of casualties among the militants.
The army has been stepping up efforts to prevent fighters from Syria using the Lebanese border town of Arsal and surrounding areas as a base. Arsal was the scene last month of the deadliest spillover of fighting in the three-year civil war in Syria and is also home to tens of thousands of refugees.