Libya’s government must halt the “unacceptable bloodshed”, said Hillary Clinton, the US secretary of state.

“The government of Libya has a responsibility to respect the universal rights of the people, including the right to free expression and assembly,” Clinton said in a statement. “Now is the time to stop this unacceptable bloodshed. We are working urgently with friends and partners around the world to convey this message to the Libyan government.”

Clinton’s statement was the highest-level statement so far by the US government in response to the civil unrest in Libya where the situation is increasingly deteriorating.

In Libya’s excelerating strife, military forces and pro-government allies have been attacking anti-government demonstrators in a bloody crackdown.

The death squads of Libyan leader Colonel Muammar Gaddafi have been strafing and bombing the city in their war planes and snipers have been opening fire of protesters.

Two Republican senators in the US have called for President Barack Obama to publicly denounce what they called “egregious violations of human rights” by the Libyan leader.

“We urge the president to speak out clearly in support of the Libyan people,” said a statement by Arizona Senator Jon Kyl and Illinois senator Mark Kirk.

US authorities were keeping a close watch on Libya’s rapidly unfolding political crisis and in particular, paying close attention to a speech made on Monday by Saif al-Islam Gaddafi – the Libyan leader’s son – which included warnings of a civil war if demonstrations in the North African country don’t stop.

A senior Obama administration official said it was looking at what possibilities might exist for meaningful reform.

In his speech, Saif Gaddafi acknowledged political change occurring throughout North Africa and the Middle East, and proposed “radical” reforms, such as bolstering local governments, relaxing restrictive laws, raising salaries, extending loans and drafting a constitution, which doesn’t exist now.

Despite the warning from Gaddafi’s son, Libya’s protesters showed no sign of backing down, CNN reports.

After Gaddafi’s government apparently lost control of the city of Benghazi, angry protesters said they hoped for a similar turn of events in the capital, Tripoli.

Hundreds of people are feared dead in the violence in Tripoli and there have been reports of a massacre in two suburbs, with armed men firing indiscriminately, leaving women and children among the dead.

The unrest, spurred largely by high unemployment and demands for freedom, has left at least 233 people dead in Libya, according to Human Rights Watch, citing hospital sources.

Tripoli residents said state-run al-Shababiya TV was attacked Sunday evening by anti-government protesters, but this could not be confirmed.

The Libyan government maintains tight control on communications.

Families of US embassy staff and non-emergency personnel have been ordered to leave Libya.

Americans have also been told to defer all travel to the country.

The growing US pressure on Gaddafi – a famously mercurial leader – is only the latest in a series of twists and turns in the relationship between Washington and Tripoli over his 42 years of rule.

In 1986, Libya was implicated in the fatal bombing at a West Berlin nightclub that resulted in the death an American service member. President Ronald Reagan ordered the bombing targets in Libya in response and imposed economic sanctions. Reagan dubbed Gaddafi the “mad dog of the Middle East.”

Two years later, Libya was implicated in the 1988 bombing of Pan Am Flight 103, which exploded over Lockerbie, Scotland.

In 1999, Gaddafi agreed to turn over suspects in the Lockerbie bombing and in 2003, he agreed to eliminate his and stockpile of weapons of mass destruction.

The moves helped Libya regain diplomatic relations with the United States in 2006.

In 2008, however, Swiss officials jailed one of Gaddafi’s sons, prompting the furious leader to cut off the country’s oil supplies, withdraw Libyan money from Swiss banks and threaten to sever diplomatic ties.

Gaddafi returned to the international spotlight again in 2009 when Scotland agreed to release convicted Lockerbie bomber Abdel Basset al-Megrahi, who was terminally ill with cancer, on compassionate grounds. He received a hero’s welcome in Libya.

Sceptics, including several U.S. senators, contend that al-Megrahi was released as part of a deal fuelled by British business interests in Libya, including oil giant BP.

Libya is one of Europe’s key oil suppliers.