Protesters forced their way into a Tripoli hotel where Egypt's military leader was meeting Libyan officials on Monday and lambasted him for failing to extradite supporters of ousted leader Muammar Gaddafi who have fled to Egypt.
The angry reception for Field Marshal Mohamed Hussein Tantawi, head of the ruling military council, will add to his problems at home, where opponents accuse him of being out of step with the "Arab Spring" revolutions which last year forced out the rulers of Egypt and Libya.
As Tantawi walked through the lobby of the Corinthia Hotel in central Tripoli, surrounded by Libyan and Egyptian security details, about a dozen protesters held up placards demanding Cairo hand over "symbols of the former regime."
Ashour bin Khayal, foreign minister in Libya's new government, tried to persuade the protesters to leave the building. But one of them shouted at him: "Fifty thousand Libyans were killed for the sake of freedom!"
Civil society activists say a number of Gaddafi lieutenants have been harboured in Egypt since the former Libyan leader was overthrown in August last year. They want them handed over to face trial.
Later, after Tantawi had left, a different group of protesters blocked the road near the hotel, preventing a bus carrying part of the Egyptian delegation from moving.
"Shame on you Field Marshal, Muammar's people are in your hands!" the protesters shouted.
Abdurrahim El-Keib, the Libyan interim prime minister, said he had raised the issue of pro-Gaddafi fugitives in his meeting with Tantawi.
"We told him that we want their support in Egypt against the figures of the former regime that have done wrong, oppressed, killed and abused the Libyan people in all possible ways," Keib told reporters.
Asked whether Cairo had promised to extradite the fugitives, he said: "This will take time, but we have raised the issue in a serious and clear way and without leaving any doubt that we are serious about this."
Relations between Egypt and Libya have become tense in the past few months. Some Libyans accuse Egypt's military council, in power since the overthrow of President Hosni Mubarak, of failing to back the post-Gaddafi leadership in Tripoli.
The commander of a powerful Libyan militia warned Egypt last month he would use force to close its embassy and shut the border if Cairo failed to take off the air a Gaddafi-era television station that he said was broadcasting from Egypt.
Libya's interim government, the National Transitional Council (NTC), distanced itself from his threat.
Libyan activists say Egypt's military is harbouring, among others, Al Tuhami Khaled, once the head of Gaddafi's internal security service who led a crackdown against Islamists in the mid 1980's.
The Libyan prime minister said after meeting Tantawi that Libya would not dispose of investments made by Gaddafi's administration in Egypt, provided they are financially sound.
"For investments (in Egypt), everything that is successful, or can be made successful, we will carry on with it," he said.
"Any investment that was based on a meaningless political decision will be seriously reconsidered."