(ABC) — The father of suspected Boston Marathon bomber called on his son today to give up peacefully, but warned the U.S. that if his son is killed “all hell will break loose.”

Anzor Tsarnaev spoke to ABC News from his home in the Russian city of Makhachkala as Boston police carried out an intense dragnet for his son Dzhokhar Tsarnaev.

Dzhokhar Tsarnaev, 19, survived a running gun battle with police during the night that left an MIT security officer dead and a Boston cop badly wounded. His older brother died in the shootout.

The father said he spoke to his sons by phone earlier this week. “We talked about the bombing. I was worried about then,” Anzor Tsarnaev said.

He said his sons reassured him, saying, “Everything is good, Daddy. Everything is very good.”

The elder Tsarnaev insisted that his sons were innocent, but said he would appeal to his son to “surrender peacefully.”

“Give up. Give up. You have a bright future ahead of you. Come home to Russia,” the dad said.

The father warned, however, “If they killed him, then all hell would break loose.”

Dzhokhar Tsarnaev, who is now described as willing to die in a battle with police, was more striking for taking acting classes, advanced placement courses and being a star athlete with lots of friends in high school.

“He never seemed out of the ordinary at all,” high school classmate Sierra Schwartz told “Good Morning America” today. “This is not someone who seemed troubled in high school or shy. He was just one of us. It’s very weird.”

Steven Owens told ABC News, “I met him when I was in seventh grade and he was just a great kid. He was fun to be around. Very studious, very smart. I don’t remember a time when he was ever having trouble in school. He was a great athlete. Great to be around.”

Owens said Tsarnaev “always had a positive attitude,” but had expressed some political opinions in school.

“He always thought the war [Iraq, Afghanistan] was stupid,” Owens said. “He didn’t enjoy the idea of war. We didn’t really talk about it much. The only time it ever really came up was when we were learning about it in school.”

When Owens first saw authorities’ photos of Tsarnaev, he wasn’t positive it was him since he hadn’t seen him in a few years.

“I started looking through my yearbook because I thought I recognized him and there he was,” Owens said. “I was just so surprised.”

The search for Tsarnaev, 19, of Cambridge, Mass., has effectively shut down Boston and its surrounding cities today, including Watertown, Mass., where Tsarnaev’s brother was killed in an overnight shootout.

Boston is on lockdown and police are engaged in a large operation in Watertown.

Law enforcement sources tell ABC News the suspects are believed to be brothers are of Chechen ethnicity and their family came from the semi-autonomous Russian province of Dagestan. A law enforcement source confirmed that at least one of the brothers is a legal permanent resident in the United States. The brothers are believed to have spent time in Kyrgyzstan.

Schwartz went to Cambridge Rindge and Latin High School with Dzhokhar, who is now the target of a massive police dragnet.

She recognized him immediately when she saw his photo released by authorities.

“I was like, ‘Wow, that looks just like Dzhokhar…,” she said. She then noticed that his Facebook page had been deleted.

Schwartz knew he went to college, but did not remember where. She last saw him in Cambridge in the summer of 2011 before starting college. She was not aware that he had a brother.

“He was a great athlete. He did well. I think he won a scholarship for it,” Schwartz said. “This is very unexpected….this is out of the ordinary. Completely shocking.”

Schwartz is still reeling from the news that her former classmate is the most wanted person in America.

“When I woke up, it’s like I’m living a nightmare right now. It can’t be described,” she said. “I just really hope they catch him.”

“We all knew him for four years and that’s something a lot of people can’t say,” she added.

Tsarnaev’s father Anzor Tsarnaev lives in Makhachkala, the capital of Republic of Dagestan.

“My son is a true angel,” Anzor Tsarnaev told the Associated Press. “Dzhokhar is a second-year medical student in the U.S. He is such an intelligent boy. We expected him to come on holidays here.”

Dzhokhar Tsarnaev’s brother, identified as Suspect 1, was killed overnight after exchanging fire with police officers, during which multiple explosive devices were detonated, authorities said.

The Monday bombing near the finish line of the Boston Marathon killed three people and injured more than 170.