PESHAWAR, Pakistan -- A suicide bomber blew himself up yesterday in a hotel restaurant popular with Afghans, killing at least 22 people and injuring scores in what might be a sign of the Afghan conflict spilling over into Pakistan's cities.
The explosion in Peshawar, a provincial capital close to the lawless tribal areas that straddle the Afghan-Pakistan frontier, came one day after a U.S. soldier was killed in an ambush on the Pakistan side of the border - a rare Western combat casualty inside Pakistan. A Pakistani soldier also was killed.
Authorities said they were investigating whether yesterday's suicide bombing was linked to "a neighboring country."
An Interior Ministry spokesman, Javed Iqbal Cheema, said it was too early to say whether the attack was tied to the weekend death of Mullah Dadullah, the top operational commander for the Taliban. Coalition forces announced they had killed Dadullah in Afghanistan's southern Helmand province after he left an unspecified "sanctuary" - widely presumed to be inside Pakistan.
The Associated Press quoted security officials as saying that a relative of Dadullah had been arrested at the bombed restaurant days earlier and that a note taped to one of the bomber's severed legs contained a warning to "spies" for the Americans.
There was no immediate claim of responsibility for the attack in Peshawar.
The bombing came against a backdrop of continuing political upheaval in Pakistan over President Gen. Pervez Musharraf's efforts to dismiss the country's chief justice.
Calm largely was restored in Karachi, the country's largest city and its financial capital, where pro- and anti-government forces fought gunbattles in the streets over the weekend that left about 40 people dead. The political opposition called a general strike Monday in protest, which disrupted commercial activity in Karachi and other cities.
At a hearing yesterday before the Pakistan's Supreme Court, a lawyer for Chief Justice Iftikhar Mohammed Chaudhry said his client had been pressured to resign.
Chaudhry is seen as a potential obstacle to Musharraf's plan to extend his presidential rule in elections this fall without giving up his rank of army general.
The confrontation, which has galvanized Pakistan's splintered political opposition, is considered the most serious challenge to Musharraf's authority since he seized power in 1999. A planned parliamentary debate on the violence in Karachi had to be postponed when opposition politicians walked out in protest.
Afghanistan and Pakistan are allied with the United States in the fight against the Taliban and other insurgent groups.
However, the two South Asian nations accuse each other of failing to adequately police their respective sides of the 1,500-mile frontier.
Zulfiqar Ali and Laura King write for the Los Angeles Times.