In the latest of a series of attacks on the Turkish military, a remote-controlled bomb killed 5 people and wounded 15 on a busy highway in Istanbul early Tuesday, the governor’s office announced.

While there was no immediate claim of responsibility, Turkish news reports suggested that the attack might have been carried out by the Kurdistan Workers’ Party, a group seeking autonomy for the more than 20 million oppressed and impoverished Kurds in southeastern Turkey. The authorities in Turkey, along with the United States and the European Union, consider it a terrorist organization. The Turkish military has been waging a war against the group since the 1980s.

“As Istanbul people, we will hold firm against terror that aims to create an air of anxiety and hopelessness,” Huseyin Avni Mutlu, the Istanbul governor, said. “We will do everything in our capacity to bring the perpetrators of this crime to justice.”

According to witnesses and police investigators, the explosion took place during the morning rush hour in the city’s Halkali district, as a military shuttle bus traveled between a residential compound and offices that include the military police headquarters.

The dead included the 17-year-old daughter of an officer, a statement from the governor’s office said, adding that the bomb, planted in advance, had been detonated by cellphone. Television news images showed the bus with shattered windows and severe damage to the rear.

A spate of recent assaults have been ascribed to the PKK, including an attack on a military outpost in the southeast two days ago that killed 11 soldiers, provoking a public outcry. This month, a bomb attack wounded 15 people on a military shuttle bus.

The attack on Tuesday also followed a warning by the group that it would carry out strikes in cities across Turkey.

Nihat Ali Ozcan, a Turkish terrorism expert, said the increase in attacks was a reaction to the government’s banning of the country’s sole Kurdish political party, even though the authorities say they are expanding Kurdish rights and broadening democracy.

The current government is the first to broadcast Kurdish television programming and to allow private Kurdish language instruction. But Prime Minister Recep Tayyip Erdogan has been criticized by some intellectuals and Kurdish activists for not pursuing broader measures, including a comprehensive amnesty to persuade the PKK to lay down arms, Kurdish language education in public schools and a constitutional recognition of Kurdish ethnic identity.

Speaking hours after Tuesday’s attack,. Erdogan called for calm and for parliamentary support for his party’s political efforts, which are referred to as the Kurdish opening.

“We will not compromise on democracy and efforts for national unity and brotherhood,” Erdogan said. “If we give up the opening, you can be sure that the winners will be the war and terror barons as well as the arms dealers, vampires who feed on the blood of the youth. We will not allow this happen.”