A strong earthquake with a magnitude of 6.5 struck central Japan early Tuesday morning, injuring more than 100 people, setting off a tsunami warning and swaying buildings 90 miles away in Tokyo. The quake struck at 5:07 a.m. Tuesday off the coast of Shizuoka prefecture, 90 miles southwest of Tokyo, and was centered about 14 miles underground, the Japan Meteorological Agency said.

The agency immediately issued a tsunami warning for parts of Japan's Pacific coast. Small waves of around 16 inches reached Omaezaki and other coastal towns in Shizuoka before the warning was lifted about two hours later.

The quake was the second strong tremor to strike Japan in as many days.

Late Sunday, an earthquake measuring magnitude 6.9 struck further off the Pacific coast, jolting a swath of central and eastern Japan. But neither appeared related to a powerful quake that experts say is due for the Tokai region, centered on Shizuoka, which could also damage Tokyo.

Seismologists have long predicted a powerful quake with magnitude 8.0 or higher along Tokai's Pacific coast, a special concern because of a large nuclear reactor in the region. Experts also warn that a separate temblor could strike below the Tokyo metropolis, killing tens of thousands of people. The two reactor units that were active at the Chubu Electric Power nuclear power station in Shizuoka automatically shut down from Tuesday's shaking and were undergoing safety checks. There was no sign that radiation had leaked from the compound, officials said.

The Tomei Expressway, a major thoroughfare linking eastern and western parts of the country, was expected to remain closed for three days because of a landslide along a section about 330 feet wide. The high-speed bullet train that runs alongside the Tomei was temporarily suspended between Tokyo and the central city of Nagoya.

Damage from the quake was compounded by a powerful typhoon in the region Tuesday, officials said. The landslide along the expressway occurred after a hill loosened by heavy rains collapsed in the quake, a civil engineer, Sasaki Tetsuya, told NHK television.

At least 14 people were killed, and 17 others were still listed as missing, after typhoon Etau slammed into the western part of the country on Monday, sparking floods and landslides.

Tuesday's quake occurred on the Philippine Sea tectonic plate, which collides and slips under the Eurasian plate near Japan, according to Takashi Yokota, head of the earthquake-prediction unit at the meteorological agency. The bigger quake predicted for the region would occur if the Eurasian plate were to buckle from its collision with the Philippine plate, Mr. Yokota said.

Japan lies near the intersection of four tectonic plates, making it especially prone to seismic activity. In June 2008, a quake with a magnitude of 7.2 struck the northern prefecture of Miyagi, killing 23.

In 1995, more than 6,000 people were killed when a quake hit the western port town of Kobe, Japan's most deadly tremor since World War II.