The blasts injure up to 100 more as police look for suspects and fear more attacks.
The Philippine government warned of more terror attacks after five powerful bombs tore through the capital Saturday, killing at least 14 people, injuring as many as 100 others and unleashing a nationwide climate of fear, blame and suspicion.
There were no credible claims of responsibility for the attacks in Manila, but plenty of theories. Police hinted that Muslim rebels could be involved. A presidential spokesman implicated communist rebels. And the powerful political opposition hinted at unidentified forces who want to distract the population from President Joseph Estrada's impeachment trial on corruption charges.
The embattled president, in a brief televised address five hours after the bombings, tried to calm nerves.
"I assure you we will use all the forces of our law enforcers to halt this violence," Estrada said. "I have directed the chief of staff of the Armed Forces of the Philippines to mobilize its intelligence agencies."
The first four blasts _ on a train and a bus and at an airport and a park _ happened nearly simultaneously, sending thousands of panicked residents rushing from buildings in fear of more bombings.
The explosion on the train was the most destructive: It blew the light railway transport train's front coach apart as it pulled into Manila's Blumentritt Station at noon. At least nine people died and scores were hurt.
"The train was approaching when I heard the explosion in the front coach," said Mari Vicpaglan, a ticket clerk. "It was so loud. I tried to help them. I felt dizzy because of the number of people pleading for help."
Elsewhere, a bomb exploded in a bus inside the main bus terminal in Quezon City, in the greater Manila area. At least one person died, 15 were hurt and the terminal was severely damaged.
A third blast came near a large aviation fuel depot at Manila's Ninoy Aquino International Airport. At least six people were hurt, said an airport official, but the fuel depot did not explode.
The fourth bomb exploded on a bench in a park near the U.S. Embassy, wounding at least nine, blasting a two-foot crater in the ground and damaging buildings some 650 feet from the embassy. The bomb apparently was not directed at the embassy itself.
Later in the day, police found a fifth bomb at a gas station near the posh Dusit hotel. They tried to defuse it, but it exploded as they worked, killing one bomb expert immediately. Another died in the hospital later.
It was not immediately clear which bombs killed the 13th and 14th victims reported by emergency services.
The attacks left many Manila residents jittery and police swamped with reports of suspicious packages. Several commercial centers were evacuated after false alarms.
Witnesses said a suspicious package on a counter in a shopping mall sparked a stampede as people fled the building. Police bomb experts found mangoes in the package.
The areas hit by the explosions were cordoned off, holding back masses of onlookers, and television stations urged people to stay away from the blast scenes.
The attacks further darkened a political atmosphere that was already tense as Estrada's future teeters on the outcome of his impeachment trial, which resumes Tuesday in the Senate. He is accused of massive corruption.
Estrada's press undersecretary, Mike Toledo, denied claims by opposition politicians Saturday that Estrada would declare a state of emergency or martial law.
Defense Secretary Orlando Mercado said police arrested one man who was carrying wires and acting suspiciously around one of the bomb sites. They have not revealed his identity.
Police suggested that the Abu Sayyaf, the smaller of two separatist Muslim groups in the southern Philippines, were to blame. The blasts came a day after Manila-area police were put on alert for holiday bombing attacks by the rebel group.
But presidential spokesman Ernesto Maceda implicated communist rebels who have been fighting the government for more than 30 years. He said intelligence reports show the communist New People's Army were planning numerous weekend attacks on rural power lines and stations.
The New People's Army is the major left-wing guerrilla group in the Philippines. It has had only informal communication with the Muslim groups.
The Philippines have long grappled with a multitude of religious and political conflicts as well as rising crime. In the south, two Muslim separatist guerrilla groups have been fighting for a separate Islamic nation.
The larger group, the Moro Islamic Liberation Front, has been blamed for bombings in Manila in the past. But Eid Kabalu, a MILF spokesman, denied it carried out the bombings. He told DZRN radio in Manila that his group didn't have the physical capacity to attack on the scale seen Saturday.
The Abu Sayyaf is the more radical of the two groups. On Thursday, police arrested Abu Sayyaf spokesman Hector Janjalani in Manila. They said he had several grenades and sketches of potential targets in the city.