South Korea's government said Wednesday it will resume imports of American beef this week, hoping to move on from a crisis that battered the pro-U.S. administration with weeks of anti-government protests over food safety.

South Korea and the United States agreed last week to restrict U.S. beef exports to younger cattle, believed to be at less risk of mad cow disease. The agreement modifies an earlier deal that placed few restrictions on meat shipments, and sparked widespread outrage against the government for caving in to Washington and ignoring the public's concerns.

Korean activists, however, have vowed to keep rallying against new President Lee Myung-bak, calling for a complete renegotiation of the original April beef accord. Lee's government has rejected a renegotiation, saying it would erode the country's international credibility.

"The observation of an agreement is very important for state-to-state relations and it is very essential to maintain national credibility on the international stage," Prime Minister Han Seung-soo said at a meeting with top ruling party leaders Wednesday, according to his office.

The Agriculture Ministry has asked the Public Administration Ministry to issue a legal notice Thursday on the resumption of American beef imports, the final administrative step required before imports can resume, according to Agriculture Ministry spokesman Lim Ki-sang.

Some 5,300 tons of U.S. beef, shipped earlier to South Korea but held in customs and quarantine storage facilities, will first undergo inspections before being put on the market, according to the Agriculture Ministry.

Faced with daily candlelight vigils against imports of U.S. beef, President Lee replaced his top advisers and apologized to the public for the second time last week. His entire Cabinet has also offered to resign.

Lee said Tuesday that he would not tolerate any illegal, violent demonstrations against the planned resumption of beef imports.

Demonstrations have dwindled in size since some 80,000 people gathered in central Seoul two weeks ago in the largest recent protest.

On Wednesday night, about 2,500 people rallied in central Seoul to condemn the government's announcement. They waved candles and chanted anti-government slogans in front of a barricade of police buses set up to block demonstrators from marching to the presidential Blue House.

Police sprayed fire extinguishers at activists as they used ropes to try to pull away a police bus. Some protesters attempted to march to the presidential office through a back alley, triggering scuffles with riot police. Hundreds staged a separate rally at a site closer to the presidential office.

More than 100 people were detained in Wednesday's rallies, but there were no reports of serious injuries, police said.

"We're infuriated because President Lee apologized to the people and said he would now listen to the voice of his people," said Kim Dong-kyu, an official at a coalition of civic groups that has spearheaded the protests. "Now we learned his apology lacked sincerity."

Kim said his group will mobilize activists at government storage facilities to block inspections of U.S. beef held there.

Opposition parties also demanded the Lee government cancel the planned legal notice, citing recent public surveys showing South Koreans still oppose the new rules on beef imports.

U.S. beef was banned from South Korea in 2003 after the first case of mad cow disease was discovered in cattle there. South Korea had previously been the third-largest market for American beef. Limited imports were allowed last year before being again suspended.

Eating meat products contaminated with mad cow disease is linked to variant Creutzfeldt-Jakob disease, a rare and fatal human malady.

U.S. and South Korean officials insist American beef is safe.