Five days after a 7.3-magnitude earthquake battered Haiti on Tuesday, rescue workers have found more survivors in the collapsed buildings amid strong aftershocks.

Rescue teams from different countries had already saved more than 70 lives, according Elisabeth Byrs, the UN spokeswoman.

International rescue teams have completed about 60 percent of the search and rescue work in the quake-ravaged Caribbean nation, according to Brazilian media reports.

But the rescue teams said they would not give up any hope of finding more survivors under the rubble of flattened buildings in Port-au-Prince, capital of Haiti.

Among the survivors was a 29-year-old American woman, who was pulled alive from a collapsed building in the University of Port-au-Prince on Saturday evening by a U.S. rescue team, after having been trapped there for 97 hours.

The U.S. team also found three people alive under the debris of a collapsed supermarket building in a suburb of the Haitian capital. An operation was under way to save them.

With the help of Mexican police and the navy, a well-trained Mexican rescue team Saturday saved a 35-year-old school teacher buried under the rubble. On Friday, the team also rescued seven survivors. Also on Saturday, an Israeli rescue team pulled a survivor from the collapsed building of the Haitian ministry of taxation.

At around 3:40 a.m. local time (0840 GMT) on Sunday, a strong aftershock hit Port-au-Prince, shattering windows of many buildings.

According to the U.S. Geological Survey, at least 14 aftershocks measuring 5 or above on the Richter scale have been recorded since Tuesday's devastating quake.

After arriving in the Haitian capital city on Thursday, the Chinese rescue team has been working round the clock, and by Saturday, the Chinese rescuers retrieved the body of Hedi Annabi, head of the UN Stability Mission in Haiti, and the bodies of eight Chinese peacekeeping police officers.

On Sunday, Chinese rescue workers were rushing to other quake-hit areas in the country as the first batch of 90 tons of relief supplies provided by China, including medicine, tents, water purification supplies, food and drinking water, arrived in Port-au-Prince.

The aid is part of a relief package worth 30 million yuan (4.41 million U.S. dollars) the Chinese government announced Friday.

On Saturday, the German government announced it would offer an additional 6 million euros (8.6 million dollars) in emergency aid to Haiti, raising Germany's aid to Haiti to 7.5 million euros (10.8 million dollars).

German Foreign Minister Guido Westerwelle said German technical workers will install water treatment facilities which could provide drinking water for 60,000 people.

Erik Solheim, the Norwegian minister of environment and international development, said on Saturday Norway will offer an additional 60 million krones (10.51 million dollars) of aid to Haiti, bringing Norway's total aid to 100 million krones.

After the quake, the Brazilian Air Force opened an "air corridor" between Brazil and Haiti, through which 100 tons of relief goods have been flown to the Caribbean nation.

The Brazilian Defense Ministry said a field hospital set up by the air force, which included operation rooms, intensive care units, X-ray rooms and labs, was put into operation. The hospital, located 10 km away from the city center, has a capacity of offering treatment for 400 injured people a day.

Also on Saturday, the Nicaraguan government sent three tons of emergency goods to Haiti.

U.S. President Barack Obama on Saturday invited two of his predecessors, George W. Bush and Bill Clinton, to help raise relief funds for Haiti.