Trump says we're 'blowing up the whole country' if Iran doesn't make deal in 48 hours

Four jailed members of the People's Mojahedin Organization of Iran (PMOI) have been executed since Sunday, the group said in a statement issued on Tuesday, with a spokesperson for the opposition group telling ABC News it fears an unfolding "massacre."

The PMOI said that members Babak Alipour and Pouya Ghobadi were executed at the Ghezel Hesar Prison in the city of Karaj on Tuesday. Their deaths followed the executions of fellow PMOI members Mohammad Taghavi and Akbar Daneshvarkar on Sunday, the group said.

Shahin Gobadi, a spokesperson for the PMOI, said in a statement sent to ABC News, "The desperate regime is intent on a massacre of the political prisoners, focused on those who are affiliated with the PMOI, the main force of the organized resistance."

"The international community should take a firm stance and condemn these atrocious crimes and take immediate action to save the political prisoners, including those affiliated to the PMOI, and combatants on death row. The time has come to adopt practical and effective measures, such as closing the regime's embassies and expelling its terrorist diplomats and mercenaries," Gobadi said.

The Israel Defense Forces will establish a "security zone" inside southern Lebanon with the military controlling the area and prohibiting the return of hundreds of thousands of residents -- even after the conclusion of the ongoing operation, Israeli Defense Ministry Israel Katz said Tuesday.

"At the end of the operation, the IDF will establish a security zone inside Lebanon -- on the defensive line against anti-tank missiles -- and will take security control of the entire area up to the Litani," Katz said, referring to the river 18 miles north of the Israeli border, in remarks released by Israel's Defense Ministry.

"In addition, the return south of the Litani of over 600,000 residents of southern Lebanon who evacuated north will be completely prohibited until the safety and security of residents of the north is ensured, and all houses in villages near the border in Lebanon will be demolished," Katz said.

"IDF forces are operating in Lebanon to protect the residents of the north and to keep direct threats away from them," Katz said.

"We are determined to separate Lebanon from the Iranian arena -- and to uproot the snake's teeth and remove Hezbollah's threat capability, and to change the situation in Lebanon once and for all with an IDF security presence in the places required -- with strict enforcement and absolute deterrence," Katz said. "Just as in Syria and Gaza -- so in Lebanon."

Katz said the IDF would follow the "Rafah and Beit Hanoun models," referring to two Gaza border towns that Israel destroyed in its offensive in the Palestinian territory.

-ABC News' Jordana Miller, Dorit Long, Joe Simonetti and Othon Leyva

President Donald Trump posted a video to social media on Tuesday appearing to show overnight airstrikes on the Iranian city of Isfahan. Trump did not post any comment or information alongside the video.

ABC News spoke with sources in Isfahan who confirmed loud explosions and the roar of jets overnight. NASA's FIRMS service detected fires at two locations in the mountains close to the city around 2:30 a.m. on Tuesday morning.

Video filmed close to the Mosalla Mosque in Isfahan showed explosions lighting up the night sky.

ABC News' Somayeh Malekian, Helena Skinner, Camilla Alcini and Joe Simonetti

Chinese Foreign Ministry Spokesperson Mao Ning confirmed at a Tuesday press briefing that three Chinese vessels crossed the Strait of Hormuz "recently."

"Three Chinese ships have sailed across the Strait of Hormuz recently and we would like to express our gratitude for the assistance provided by the relevant parties," Mao said.

"The Strait of Hormuz and its nearby waters are important international trade channels for goods and energy. China calls for a ceasefire and the resumption of peace and stability in the Gulf as soon as possible," she added.

-ABC News' Karson Yiu