The nearly simultaneous explosions in Jolo, capital of Jolo Island, and Zamboanga on the island of Mindanao led police to suspect the blasts could be the work of guerrillas fighting for a separate Islamic state in the predominantly Christian Philippines.
Abu Sayyaf rebels are holding 21 hostages, including 19 foreigners, in a mountaintop hide-out on Jolo Island, and a team of doctors returning from the guerrilla camp after the explosions said one of the hostages was reportedly nearly three months pregnant and should be freed.
In the town of Jolo, witnesses saw three men throw grenades from the second floor of the public market, with two of the devices exploding in a rice stall and the third in a crowded alley, police chief Muhammad Alamia said. Four people were killed and at least 39 others were wounded, police said.
Another explosiondescribed by police as "a very powerful homemade bomb"killed one woman in Zamboanga and wounded at least 19 other people, hospital officials said.
The bomb in Jolo reduced the storefront bakery to a shell of rubble. Rescuers carried the wounded to ambulances through puddles of blood and shreds of clothing. Some were treated on the spot, as anxious onlookers hovered nearby on a crowded street.
The wounded on Jolo were taken to hospitals where their screams joined the wailing of friends and relatives. Victims lay on the emergency room floor, wet with blood, while doctors treated them.
"I heard explosions, then everybody started falling to the ground," said Basir Kasim, a market worker whose shirt and hands were covered with blood from carrying the wounded. "Everybody started running away. There were a lot of bloodied people."
A doctor asked a TV cameraman to focus the camera's light on a patient in the dim emergency room so he could see to operate.
The doctors who treated the wounded had earlier visited the hostages at the Abu Sayyaf hide-out and said South African hostage Monique Strydom informed them she was two months pregnant when the group was seized 26 days ago from a Malaysian diving resort.
"As physicians, we should recommend that she be freed from that kind of situation," said Nelsa Amin, Jolo's chief government doctor.
Amin said the medical team also visited an ailing German captive, Renate Wallert, 57, whose freedom is to be the first topic of negotiations.
Amin said she suffers from high blood pressure and severe back pain, making it difficult for her to walk.
Philippine officials say the rebels have demanded $2 million for Wallert's freedom, but the government has ruled out paying a ransom.
In Berlin, private TV stations reported that Wallert said that she had conteplated suicide in captivity. It also said Wallert's son Mark and husband, Werner, are hostages.
The private German channels SAT.1 and RTL showed footage of the first TV interviews with Wallert, who rolled her head and broke into tears repeatedly.
Wallert said in recent days "I wanted to die ... but in such a situation you have thoughts like that." She said she considered suicide, but her son dissuaded her.
In a quavering voice, Wallert said "today it's going good for me, I could walk a bit," and that someone had given her water so she could be bathed.
Besides the South African and German women, the Abu Sayyaf rebels are holding another South African, two more Germans, two French citizens, two Finns, a Lebanese, nine Malaysians and two Filipinos.
Negotiations for the hostages' release were likely to start Friday or Saturday, Libyan envoy and negotiator Abdul Rajab Azzarouq said.
He said negotiators sent envoys to the rebels on Thursday to discuss a place and date.
The Abu Sayyaf rebels are also holding about eight Filipino hostages on the nearby island of Basilan.
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