The United States condemned Monday what it called the "senseless attack" in northern Lebanon that security officials say killed four Lebanese soldiers.

"We condemn the senseless attack today on a bus carrying Lebanese army troops in Tripoli, Lebanon," State Department deputy spokesman Robert Wood said in a statement.

"This incident is particularly abhorrent as it comes during the holy month of Ramadan," he said.

"We express our deep condolences to the Lebanese Armed Forces and the families of those soldiers and civilians killed in the attack," he added.

"This tragic event further underscores the importance of bringing all arms in Lebanon under the control of the state. The United States remains firmly committed to supporting Lebanon's state institutions and its security services.

"We support the Lebanese government and its efforts to bring the perpetrators of this terrible attack to justice," according to Wood's statement. (AFP)