DIYARBAKIR, Turkey, March 18 (Reuters) - Turkish bomb-disposal experts disabled an explosive device in a vehicle found overnight near a government building in southeast Turkey, security sources on Friday as a recent spate of bomb attacks prompted security warnings in major cities.
The vehicle was found with 150 kg (331 lb) of explosives in the town of Hani in the mainly Kurdish region's Diyarbakir province, the sources said. Police were examining security cameras in the area as part of the investigation.
Kurdish militants on Thursday claimed a suicide bombing in Ankara that killed 37 people this week and warned of further attacks, while Germany shut down its diplomatic missions and schools in Turkey.
The US embassy in Ankara issued a statement overnight saying its citizens "should be mindful of their security precautions," noting Kurdish New Year (Newroz) celebrations taking place this weekend and saying large events can turn confrontational and escalate into violence.
"The US Embassy also reminds individuals that terrorist organizations have targeted transportation hubs, Turkish government facilities, and public spaces in the recent past," it said.
Last Sunday's suicide bombing was the second in a month in the heart of Ankara claimed by the TAK militant group, opening a dangerous new phase in Turkey's war with Kurdish militants as deadly attacks spread to its biggest cities well beyond the southeast where conflict is usually focused.
Also on Friday, an unidentified gunman killed a police officer and a civilian in a shootout in central Ankara, Cumhuriyet newspaper said.
The attack occurred in the Dikmen area of the Turkish capital, it said, without giving further details.
The German Foreign Ministry released a statement on Friday saying it will close all diplomatic missions and German schools in Turkey until the weekend due to a highly credible security threat.
"How long the danger remains, I can't say. But the fact is that due to the current assessment of the situation, we have decided to keep the embassy and schools closed until the weekend," the spokeswoman told a government news conference.