Israeli forces have detained two young adult American brothers in Gaza and their Canadian father in an overnight raid on their home in the besieged Palestinian territory, relatives of the men say.

A US embassy official in Jerusalem said American officials were aware of the situation and following up with Israeli authorities.

The Israeli foreign ministry and military have yet to comment.

Borak Alagha, 18, and Hashem Alagha, 20, two brothers born in the Chicago area, are among fewer than 50 US citizens known to still be trying to leave sealed-off Gaza amid Israel’s military offensive.

Numerous other US green-card holders, close relatives of the citizens and permanent residents also are still struggling and unable to leave, despite US requests, according to their American families and advocates.

Cousin Yasmeen Elagha, a law student at Northwestern University, said Israeli forces entered the family home in the town of al-Masawi, near Khan Younis, around 5am Gaza time today.

The soldiers tied up and blindfolded the women and children in the family, and placed them outside the home, the cousin said.

The two American brothers, their Canadian citizen father, a mentally disabled uncle and two other adult male relatives were taken away by the Israelis, and remain missing, Ms Elagha said.

Men of a neighbouring household were also taken away. So were other adult male relatives of another Alagha household, for a total of about 20 detained, the US cousin said.

A family social media account from Gaza also described the detentions.

State Department spokespeople in Washington had no immediate comment on the reported detention of the American brothers.

The brothers would be among three American citizens taken into custody by Israeli forces this week, during the same time secretary of state Antony Blinken visits the region in an effort to mediate with ally Israel and regional Arab leaders.

A 46-year-old Palestinian American woman, Samaher Esmail, was taken from her home in the occupied West Bank on Monday and detained. The Israeli military said she had been arrested for “incitement on social media” and held for questioning.

The US embassy in Israel said today it had no updates on her case.