Defense Minister Ehud Barak said on Sunday that Israel Defense Forces soldiers succeeded in defending Israel's sovereignty when Palestinian refugee demonstrators breached the border with Syria and attempted to cross the border with Lebanon.

Barak cautioned, however, that Israel will in the future have to deal with similar and perhaps more complex incidents.

IDF forces opened fire on demonstrators on the Syria border, apparently killing several of them.

The IDF and the Lebanese army have presented different versions of the incident in the Lebanese village of Maroun a-Ras. The IDF said that gunfire from Lebanese army soldiers killed a number of demonstrators while the Lebanese army claimed that IDF soldiers killed 10 demonstrators.

In an interview on Channel 2, Barak responded to the charge that there were not enough IDF forces in place on the northern borders, saying that it was impossible to fully prepare for events like those that occurred on Sunday.

"The IDF must protect the sovereignty of Israel and it succeeded in doing so," Barak said.

Barak said that the incident on the Syrian border would have to be investigated.

"I expect investigations to be done so that lessons can be learned," he said. "There were deaths there in several places and we regret the deaths. Those responsible for this are those who attempted to violate Israel's sovereignty and those who sent them, if there are any."

Barak also warned that "we are just at the start of this matter and it could be that we'll face far more complex challenges."

Barak said that IDF soldiers acted with restraint and discretion and only opened fire at the legs of protesters when other crowd dispersal methods proved insufficient.