ANKARA, Turkey (AP) – An explosion Monday in the Mediterranean city of Antalya killed three people and injured 18 others in the second blast in a Turkish resort area in as many days, private NTV television said.

A hard-line Kurdish militant group claimed responsibility for the Sunday night bomb attack that injured 21 people, including 10 British tourists, in Marmaris.

The Kurdistan Freedom Falcons, which has links to Turkey’s main Kurdish guerrilla group, the Kurdistan Workers Party, warned on its Web site that “Turkey is not a safe country, tourists should not come to Turkey.”

Firefighters who put out a blaze ignited by Monday’s blast discovered two burned bodies in the street, police spokesman Akif Aktug told the state-owned Anatolia news agency.

An injured person died later in a hospital, NTV reported.

Eighteen other people were injured in the explosion in front of a city-run business center near the gate of a historic castle in downtown Antalya, NTV said.

“The cause of the explosion is still under investigation,” said Guzide Ormeci, a spokeswoman for the governor’s office.

CNN broadcast images from the resort town showing the injured arriving at the hospital in taxis or lying on the ground at the scene of the blast, waiting to be loaded into ambulances.

The windows of the building’s first two floors all appeared to have been blown out.

Antalya is a popular resort city that attracts millions of Russian and German tourists each year.