A cease-fire around the secessionist stronghold of Aden reportedly collapsed after a few hours Thursday, and foreign diplomats said warplanes from the rebellious south bombed an oil field in northern Yemen.
A senior southern official said northern troops launched heavy attacks on besieged Aden and southern forces defending the port struck back, marking the seventh truce to quickly fail in the 2-month-old civil war. There was no immediate comment from the northern government in San`a.Diplomats in San`a, who spoke on condition of anonymity, reported later that southern warplanes attacked the Marib oil field about 60 miles east of the capital. They said a processing unit and storage tanks were set on fire.
Meanwhile, Russian news agencies said that at talks in Moscow, envoys from the north and south signed a truce accord Thursday intended to halt the war. The agreement was separate from the failed truce at Aden.
There was no confirmation from either party to the conflict, which began May 4 after northern and southern leaders failed to resolve disputes over sharing power in the 4-year-old union of North and South Yemen.
The Russian news agency Interfax said the open-ended truce was to begin at midnight Thursday in Yemen and both sides agreed to hold further talks in New York on monitoring the cease-fire.
The negotiations mediated by Foreign Minister Andrei Kozyrev of Russia were part of Moscow's efforts to regain influence lost in the Middle East after the collapse of the Soviet Union.
The Kuwaiti news agency Kuna had said the truce at Aden was to have lasted until Saturday morning, to allow the delivery of humanitarian aid by the Red Cross.
But Mohsen Mohammed, deputy prime minister in the southern secessionist government, said northern troops began violating the cease-fire within an hour after it took effect at 8 a.m.
Speaking to The Associated Press in Bahrain by telephone from Saudi Arabia, he said northern artillery and tanks fired on Aden suburbs for nearly four hours before southern troops retaliated. "We had to deal with it," he said.
Southern leaders are urging foreign intervention to halt the fighting and want an international monitoring force to maintain a cease-fire. The northern government opposes that.