The United States, France and Britain have asked Libya's neighbors to beef up security on their borders to prevent the possible smuggling out of weapons, Algerian paper al-Habar said.
The West is afraid that in the chaos of Gaddafi's downfall the leftovers of his military capabilities could fall into hands of al-Qaeda or other militant groups.
No one can be sure who is now controlling the Libyan government's weapons stockpiles, a stew of deadly chemicals, raw nuclear material and some 30,000 shoulder-fired rockets, the paper said.
The leaders of Algeria, Tunisia, Egypt, Chad and Niger received letters in which Western leaders requested that measures be taken to prevent such groups obtaining the weapons, the paper said.
The West also warned the countries adjacent to Libya against giving refuge or transit passage to the members of the toppled regime, the paper also said.
Rebels seized control of much of Tripoli this week, but Colonel Gaddafi's whereabouts remain unknown. According to a pro-Gaddafi television channel, the 69-year-old promised "martyrdom or victory" in his fight against the rebels and NATO forces.