ISLAMABAD — Security forces killed as many as 70 militant supporters of a pro-Taliban cleric, the army said today, hours after a suicide attack on an air force bus killed eight and wounded 40.

Opposition leader Benazir Bhutto, seen by many supporters as key to a possible return to democratic rule, flew out of Pakistan to visit family in Dubai, United Arab Emirates, two weeks after she was targeted by assassins upon her return from eight years in exile.

Terror attacks and clashes between militants and President Musharraf’s security forces have deepened the political turmoil ahead of a Supreme Court ruling on whether General Musharraf’s sweeping October 6 presidential victory was constitutional. There are fears he could impose a state of emergency if judges rule against him, jeopardizing the country’s transition to civilian rule.

“She has gone to Dubai to see her ailing mother and children,” Ms. Bhutto’s spokesman Farhatullah Babar said this afternoon after the former prime minister was seen stepping onto an Emirates plane in Karachi. “She will come back on November 8.”

The militants in the northwest district of Swat attacked law-enforcement posts before dawn today, and security forces responded with fire from mortars, small arms, and helicopter gunships.

“According to the information I have from police and Frontier Constabulary, between 60 to 70 miscreants were killed in Swat’s areas of Khawaza Khela today,” an army spokesman, Major General Waheed Arshad said.

The suicide bombing on the Pakistan Air Force bus occurred at around 7 a.m. near an air base in Sargodha, about 125 miles south of Islamabad, an air force spokesman, Sarfraz Ahmed, said. All the dead were air force employees, an official at the hospital treating the victims, Sahid Malik, said.

General Musharraf, who seized power in a 1999 coup, has pledged to quit the army before starting a new presidential term, but declined on election night to say whether he would accept a negative verdict from the court.

The doubts over his political future and what course he might take if blocked from a new five-year term has added to the climate of uncertainty.