Published: May 15, 2010 5:57 PM EDT

BANGKOK (AP) - Thailand's beleaguered prime minister says he is attempting to quell violence in Bangkok with minimum bloodshed, but he's vowing not to bow to anti-government demonstrators demanding his resignation.

Prime Minister Abhisit Vejjajiva's comments on national TV come after three days of street battles between troops and Red Shirt protesters that have left 22 people dead and more than 170 injured.

Saying the only way to end the loss of life "is to have the protesters end their protests," the prime minister asserted that "terrorists" have infiltrated the Red Shirts.

Earlier in the day, the Thai army designated an area in central Bangkok as a "live firing zone" in a warning to both protesters and local residents. Soldiers unrolled razor wire across roads leading to the commercial area with hotels and shops. They pinned Thai and English-language notices saying "Live Firing Zone" and "Restricted Area. No Entry."

Meanwhile, the U.S. Embassy in Bangkok is offering to evacuate family members of its staff in the volatile Thai capital. It's also issued a travel warning advising American citizens to stay away.