Israel has arrested and charged an Israeli Arab for traveling to Syria to fight with rebels in the civil war against Syrian President Bashar Assad. His remand was extended by two weeks on Wednesday, Israel Radio reported.

The Shin Bet internal security service said that Hakmat Matzrawa of Taibe was arrested last month. The 29-year-old admitted that he entered Syria via Turkey and received military training from Syrian rebels. The report did not specify which rebel group Matzrawa joined.

According to the Shin Bet, Matzrawa said that he made the trip in part to seek information about his brother Hussein, who had gone to Syria to join the rebels several months ago.

While with the rebels, Matzrawa said that he was questioned extensively about Israel, especially about the IDF and the Dimona nuclear reactor.

The rebels asked Matzrawa to carry out a suicide attack inside Israel, or against President Bashar Assad’s regime, but he refused, according to the Shin Beit.

Matzrawa was charged on Wednesday with contacting a foreign agent, receiving military training and leaving Israel illegally. He was arrested at Ben Gurion airport in March immediately after his return to the country from Turkey.

Israel has attempted to avoid full-scale involvement in the Syrian civil war, which has inched dangerously close to its northern border and has spilled over into the Golan on several occasions.

Although Israel and Syria have maintained an effective truce since the end of the 1973 Yom Kippur war, the two countries are still technically at war and Israeli law prohibits travel by its citizens to an enemy state.