Thousands of Panamanians dressed in black and shouting anti-American slogans marched through the capital to mark the first anniversary of the U.S. invasion that ousted former dictator Manuel Noriega.

"I am here to protest the crime committed by the North Americans against Panama," said Teodoro Frias, 39, a University of Panama professor. "We are here to honor our martyrs who died on Dec. 20."The thousands of demonstrators marched Thursday from downtown Panama City to the El Chorrillo slum, which was destroyed during the invasion. They carried Panamanian flags and shouted "Panama si, Yanquis no (Panama yes, Yankees no)."

In other protests to mark the invasion, demonstrators burned effigies of President Guillermo Endara and Noriega and held a candlelight vigil.

The Dec. 20, 1989, invasion ended 21 years of military rule as 25,000 U.S. troops swarmed into Panama, ousted Noriega and installed Endara's civilian government.

Endara, who was sworn in on a U.S. base as the invasion began, declared Thursday a "National Day of Reflection" and government offices were closed.

In El Chorrillo, residents hung black banners from their doors and lighted candles early Thursday morning. Candles and small fires burned on the vacant lot where Noriega's military headquarters once stood.

Relatives of the dead held a Mass at the Jardin de Paz cemetery in Panama City where 123 Panamanians killed in the invasion were buried in a common grave.

The invasion caused more than $1 billion in damage and left thousands homeless and more than 500 Panamanians dead. Twenty-three U.S. soldiers were killed in fighting.

Relatives of invasion victims also held a candlelight vigil before dawn Thursday and called for a moment of silence at 12:45 a.m., the time the invasion began one year ago. Mourners sang the national anthem and burned the effigies of Endara and Noriega.

Some shouted, "Down with the gringos."

"We are marching against the invasion, in remembrance of the martyrs who died on Dec. 20, and to protest the U.S. occupation of Panama," said Juan McKenzie, one of the organizers.

While most Panamanians celebrated the overthrow of Noriega, many are now disenchanted with Endara.

Endara is widely viewed as a weak leader.