By Seyhmus Cakan
DIYARBAKIR, Turkey (Reuters) - Kurdish militants detonated a bomb under a military vehicle in southeast Turkey, wounding four soldiers, security officials said on Tuesday, in a potential challenge to a fledgling peace process between Ankara and the rebels' jailed leader.
Turkish intelligence officials and Kurdistan Workers' Party (PKK) leader Abdullah Ocalan, imprisoned on an island near Istanbul, began talks last October aiming to end a 28-year-old insurgency in which more than 40,000 people have been killed.
As the discussions have advanced, violence has dwindled, with one of the most recent PKK attacks coming in January, when its fighters killed a Turkish police officer in the southeastern province of Mardin.
In Monday's vehicle bomb attack, militants remotely detonated roadside explosives under a military convoy on a road in the Lice district of Diyarbakir province. Four soldiers in an armored vehicle were lightly wounded, officials said.
Turkish military units were hunting the perpetrators, Diyarbakir Governor Mustafa Toprak said.
According to Kurdish politicians, the PKK has been observing a de facto ceasefire since the peace process got under way and Ocalan plans to declare an official halt to hostilities by the Kurdish New Year on March 21.
But Turkish warplanes have continued to bomb militant targets in the mountains of northern Iraq where thousands of rebels are based, drawing warnings from the PKK that they are jeopardizing the peace process.
Military operations have also continued in southeast Turkey. Soldiers backed by helicopters have launched an operation around Cudi mountain in Sirnak province near the Iraqi border, with artillery units shelling the mountain, officials said.
Interior Minister Muammer Guler said Turkey's fight against the militants would continue despite the peace process.
"The struggle with terrorism, with terrorists, will never be halted. This has nothing to do with the settlement process," Guler told reporters on Tuesday.
There was no comment from the PKK on Monday's attack but the group did issue a statement saying its rebels had attacked a security post in Mardin province, west of Sirnak, in response to military operations. There was no word on casualties.
Under a plan discussed by Ocalan and government representatives, the PKK would end hostilities and give up its demands for autonomy for Turkey's largely Kurdish southeast in return for greater Kurdish rights, enshrined in the constitution, Turkish media have reported.
Star newspaper, which is close to the government, said the PKK leadership in northern Iraq had given its support to Ocalan's peace plan and would complete the withdrawal of its militants from Turkish territory by the end of June.
The paper did not specify a source for its report. There have been many media reports setting out timetables for the peace process but none have been confirmed.
(Writing by Daren Butler; Editing by Nick Tattersall and Pravin Char)