DIYARBAKIR, Turkey, Jan 4 (Reuters) - The death toll from a bomb explosion in southeast Turkey's largest city has risen to five, including three children, and the number of injured stands at 110, security sources said on Friday.

Eight of the injured are in a serious condition and the death toll could increase further, they said.

The bomb, which exploded in the centre of Diyarbakir on Thursday evening, targeted a military service vehicle that had been carrying 46 army personnel as it passed near a school. The bomb was set off by remote control.

Nobody has claimed responsibility for the blast but authorities have blamed militants of the outlawed Kurdistan Workers Party (PKK), whom Turkish security forces are battling both in Turkey and in nearby northern Iraq.

State prosecutors have granted security forces "unlimited search" powers for 16 days, enabling them to search homes, offices and vehicles in Diyarbakir, a city of 1 million people, without seeking prior permission.

Police have so far detained 12 people for suspected involvement in the explosion, the security sources said.

Turkey's President Abdullah Gul and Prime Minister Tayyip Erdogan reaffirmed their determination to crush the PKK after the blast. General Yasar Buyukanit, head of Turkey's powerful military General Staff, was expected in Diyarbakir on Friday.

The blast has reinforced the pressure on Turkey's politicians and generals to keep up an aerial bombardment campaign against PKK positions in mountainous northern Iraq.

Ankara blames the PKK for the deaths of nearly 40,000 people since the group launched its armed campaign for an ethnic homeland in southeast Turkey in 1984.

The United States and the European Union, like Turkey, classify the PKK as a terrorist organisation. The U.S. military is sharing intelligence with Turkey to help combat the PKK.

Gul is due to discuss the PKK and northern Iraq during talks next week in Washington with U.S. President George W. Bush. (Reporting by Seyhmus Cakan, writing by Gareth Jones; Editing by Charles Dick)

AlertNet news is provided by