The United States has moved military forces closer to Libya since the Benghazi attack so they will be ready to respond to threats against diplomatic personnel, a Pentagon spokesman said Monday.

"We are prepared to respond if necessary, if conditions deteriorate or if we were called upon," spokesman George Little told reporters.

A powerful car bomb exploded Monday near a hospital in the Libyan city of Benghazi, killing and wounding dozens in what officials said was the first such attack on civilians since Moammar Gadhafi's ouster.

Officials gave contradicting death tolls, however, as information trickled in about the devastating bombing which destroyed a restaurant and damaged cars and buildings near Al-Jala hospital in the center of Benghazi.

The cousin and former aide of slain Libyan leader Moammar Gadhafi appeared in court on Monday charged with the attempted murder of Egyptian police officers, Agence France Presse reported.

Ahmed Qaddaf al-Dam denied the charges which also included possessing unlicensed weapons and resisting arrest.

Two police stations were bombed early Sunday in the eastern Libyan city of Benghazi, a security official said, the second such attack in days that caused damages but no casualties.

"There were two new attacks today targeting al-Gwarcha and al-Uruba police stations, and both buildings have been lightly damaged," the official said on condition of anonymity.

The United States and Britain both announced Friday that they were withdrawing some diplomatic staff from Libya, amid security concerns over a recent flare-up in political unrest there.

Tensions have risen in Libya since ex-rebels besieged two ministries at the end of last month in a row over a law that would ban officials who served under slain dictator Moamer Kadhafi from holding office.

A pregnant woman, her husband and their three children died on Friday when their old, two-story house collapsed in the center of the Libyan capital, a neighbor said.

"The family were all sleeping in the same room when the building collapsed," said the man identified only as Mohammed, who helped in rescue efforts. "They all died."

Bomb attacks targeted two police stations in the eastern Libyan city of Benghazi on Friday, causing extensive material damage but no casualties, a security official said.

"Unknown individuals threw explosive devices at the police stations in Ras Obeida and Al-Madina," the official told Agence France Presse.

U.S. Secretary of State John Kerry on Thursday vowed to "leave no stone unturned" to find out what happened during an attack on a U.S. mission in Libya last year in which four diplomatic staff were killed.

But he refused to wade into the issue more fully during a trip to Rome, after U.S. diplomats testified on Wednesday that the State Department could have done more to safeguard the Benghazi diplomatic outpost.

Libyan Prime Minister Ali Zeidan announced on Wednesday a cabinet reshuffle "in the coming days," against the backdrop of a political crisis sparked by gunmen besieging two ministries.

"There will no doubt be a ministerial reshuffle in the coming days," he told a press conference, without specifying which portfolios would change.

Libya's defense minister resigned on Tuesday but then changed his mind and the army chief of staff was sacked, as a political crisis deepened over gunmen besieging government ministries.

"I find myself compelled, despite opposition from my colleagues in recent days, to present (my resignation) voluntarily and without hesitation," Mohammed al-Barghathi said, quoted by the official Lana news agency.