Baghdad, Iraq ? Foreign contractors scrambled to catch planes leaving Iraq on Thursday, even as three Japanese hostages were released and the Pentagon announced it was beefing up U.S. forces in Iraq by extending tours of duty.

In another tense day, an Iranian diplomat was killed in Baghdad, two American soldiers died and top U.S. military officials warned that they cannot wait much longer before launching new offensive operations against insurgents in Fallujah and Najaf.

The deaths of the two soldiers, one by a bomb and the other from an “acute cardiac event,” raised the April toll to 89, the most in one month since U.S. troops arrived 13 months ago in Iraq.

Russia evacuated several hundred workers in three charter planes Thursday. Other countries also have urged their civilian contractors to leave Iraq until the crisis subsides.

Coalition officials have said about 40 hostages from a dozen countries had been kidnapped, though many have been released. Japanese officials were investigating a report that two more Japanese civilians were taken hostage.

The three Japanese who were released were handed over to the Islamic Clerics Assn. and later taken to the Japanese Embassy.

When their blindfolds were removed, they initially didn’t comprehend that they were free.

“I thought I would die,” said Naoko Takato, 34, a volunteer aid worker. “Is this really Baghdad?” she asked. Takato later collapsed in tears of relief.

The release was greeted with joyful screams in Japan, where family members of the hostages were in the midst of a news conference in Tokyo. Family members crowded around a small television set and broke into elated screams when the hostages appeared on screen.

“Wow, here he is!” Noriaki Imai’s brother, Yosuke, shouted. Imai’s father, Takashi, collapsed on his knees and bowed to the television.

Yosuke Imai, right, brother of 18-year-old Iraq hostage Noriaki Imai, reacts in joy as he is hugged by Toru Miura, cousin of another hostage, Soichiro Koriyama, a 32-year-old freelance journalist. The families rejoiced Thursday after hearing news in Tokyo that three hostages had been released unharmed in Baghdad.