An explosion Thursday in a pickup truck in the eastern Bekaa Valley killed a Lebanese man and three Syrian nationals, the state-run National News Agency said..

News reports said the truck, carrying smuggled fireworks, blew up at 5:00 am near the town of Nabi Sheet on the Lebanese-Syrian border.

NNA, however, said that while two pickup trucks were exchanging smuggled goods on the Lebanese-Syrian border between the eastern towns of Nabi Sheet and Yahfoufeh, the truck carrying fireworks exploded, killing a Lebanese man and three Syrians.

It identified the Lebanese victim as 30-year-old Radwan Ahmed al-Fann.

The alleged smuggling operation came a few days after the independent U.N. team assessing the monitoring of the boundary said that progress in fortifying Lebanon's border with Syria has been minimal.

It also said in its report that the eastern border remains "penetrable."

"Lebanon has not yet succeeded in enhancing the overall security of its borders in any significant manner," the report noted.