Tunis/Sana'a/Algiers, Feb 26 (IANS) Libyan leader Muammar Gaddafi desperately hung on to power as international pressure mounted on him to quit, with the US imposing sanctions following a ruthless crackdown on protesters. The Arab world continued to witness unrest and Tunisia where it all started saw fresh protests to demand removal of the interim prime minister.

In Libya, troops supporting Gaddafi went on with their killing spree, with a report from Tajoura town saying that live ammunition was used against anti-government demonstrators. An estimated 1,000 people have died in the uprising that began Feb 14 against the four-decade rule of Gaddafi.

While in Yemen four people were killed in clashes that took place Friday night, Tunisia's caretaker government promised to hold elections in mid-July instead of September as protests again took place to seek removal of interim prime minister Mohammed Ghannouchi.

In Algeria, hundreds of protesters Saturday took part in demonstrations.

Libya was on the edge Saturday as anxious people wondered what Gaddafi might do to quell the unrest that started from Benghazi city in the east and quickly spread across the country.

Abu Yousef, a local resident, told Al Jazeera from Tajoura town Saturday that live ammunition was being used against anti-government protesters.

"Security forces are also searching houses in the area and killing those who they accuse of being against the government," he was quoted as saying.

Looking at the rapidly rising toll in the unrest, international pressure considerably increased on Gaddafi to step down.

The US late Friday imposed unilateral economic and weapons sanctions on Libya's government. US President Barack Obama cited the Libyan government's "continued violation of human rights, brutalisation of its people and outrageous threats", DPA reported.

The sanctions target the assets and property of the Gaddafi government, its senior officials, Gaddafi's children and Libyans who have ordered or participated in "the commission of human rights abuses related to political repression in Libya", according to an official letter sent by Obama to leaders of the Senate and House of Representatives.

As the US stepped up pressure, Gaddafi's son offered to hold talks with protesters.

In remarks delivered late Friday, Saif al-Islam Gaddafi denied that mercenaries have taken part in attacking protesters after witnesses said mercenaries from Chad, Mali and other African countries have been involved in attacks on protesters.

Saif al-Islam Gaddafi also vowed that the state would regain control over eastern cities. Witnesses said protesters are now in control of most of the eastern cities, including Benghazi, the second-largest city after the capital, Tripoli.

The UN Security Council Saturday may adopt sanctions against Libya aimed at stopping the bloodshed in the country.

The UN Secretary-General Ban Ki-moon called on the Security Council Friday to promptly consider specific steps against Gaddafi's government, with options ranging from sanctions to assured punishment.

While Libya burnt, there were fresh clashes in Yemen that left four people dead Friday night.

CNN quoting medical officials reported that four people have died from gunshot wounds after clashes in southern Yemen.

Yemen has been witnessing widespread demonstrations against President Ali Abdullah Saleh who has been in power since 1978.

The clashes also left at least 26 people injured, according to doctors and medical staff at Naqeeb Hospital in the southern port city of Aden.

On Friday, thousands of anti-government demonstrators - mostly students - who were gathered near Sana'a University in the nation's capital, were countered by a pro-government demonstration on Tahrir Square.

Saleh has promised not to run for president in the next elections due 2013 but refused to step aside immediately.

In Tunisia, where the unrest originally began and spilled over to other countries in north Africa and the Middle East, the caretaker government promised to hold elections in mid-July instead of September as protests resurged in the country seeking immediate removal of the interim prime minister Mohammed Ghannouchi.

Tunisia's longtime leader, Zine el-Abidine Ben Ali, was forced out of office in Jan 14 following a revolt - which is now described as the Jasmine Revolution.

According to BBC, police cleared the demonstrators who marched through the capital Tunis Friday demanding the resignation of Ghannouchi, a long-time ally of the ousted leader Zine El Abidine Ben Ali. Ghannouchi had served under Ben Ali since 1999.

In Algiers Saturday, protesters took part in the first demonstrations held in Algeria since the lifting of the 19-year-old state of emergency earlier this week, DPA quoted witnesses as saying.

The protesters gathered in the centre of the capital Algiers, despite the protest ban which is still in place.

Latest reports from Iraq Saturday said that at least 23 people had been killed in the massive demonstrations for political reforms that took place Friday.

Tens of thousands of Iraqis surged into the streets in at least a dozen demonstrations across the country, storming provincial buildings, forcing local officials to resign and freeing prisoners, the Washington Post reported.