The Pentagon has confirmed two Ukrainian Sukhoi-25 fighter jets were shot down near the Russian border Wednesday.
Ukraine's Security Council said the jets may have been brought down by missiles fired from Russia, but a Pentagon spokesman said it's too soon to determine what type of weapons were used, or where exactly the shots came from.
The Sukhoi-25 fighters were shot down at 1:30 p.m. local time Wednesday over an area called Savur Mogila, about 20 miles south of the site of the Malaysia Airlines Flight 17 wreckage.
Defense Ministry spokesman Oleksiy Dmitrashkovsky said the planes may have been carrying up to two crew members each.
The pilots ejected from the planes but it is not known if they survived, Fox News confirms.
The separatist group Donetsk People's Republic said in a statement on its website that one of the pilots was killed and another was being sought by rebel fighters.
Separatist fighters have claimed responsibility for shooting down the jets but the council’s spokesman was skeptical if they had the weaponry to do so.
"They were shot down very professionally. The terrorists do not have such professionals," said Andriy Lysenko, according to Reuters.
A message posted on a social media page associated with a rebel leader said the jets were shot down by rebels using MANPAD shoulder-fired, surface to-air missiles, The Wall Street Journal reports.
Video posted on a social media page appeared to show planes burning in grassy fields.
Fox News' Justin Fishel and The Associated Press contributed to this report.