Immigration police accompanied by Israeli soldiers carried out the late-night operation to seize Eva Novakova, a Czech citizen, from her home in central Ramallah, lawyer Omer Shatz told AFP.

"Her visa had expired, but that's not a reason for them to arrest her," he said, adding that the Israeli interior ministry has no authority to operate in the Palestinian territories.

"The ministry of the interior was acting outside of the sovereign territory of Israel... They wouldn't invade Poland to arrest someone."

He added that Novakova had since been escorted to Ben Gurion Airport in Tel Aviv, and the Czech foreign ministry said it was expecting the Israeli authorities to send her home on Tuesday.

"We are informed about the case. The woman... should be deported tomorrow," Czech foreign ministry spokesman Milan Repka was quoted as saying by the Czech News Agency.

The 28-year-old had been working as a media coordinator for the pro-Palestinian International Solidarity Movement.

The Israeli military would not immediately comment on the incident.

Dusan Kralik, consul at the Czech embassy in Tel Aviv, told the Czech news site iDNES: "She was detained because she stayed in the country beyond the permitted five months."

In recent months, Israel has arrested scores of Palestinian activists involved in weekly West Bank protests against its controversial separation barrier, but arrests of foreigners are extremely rare.

It is also rare for Israel's military to carry out raids inside major towns in the occupied West Bank, which are administered by the Western-backed Palestinian Authority.

Last week, Amnesty International protested against the detention without trial of three leading Palestinian activists, saying they may be "prisoners of conscience" held for protesting over the barrier.

Two of the men have not been charged with any offence, while Abdullah Abu Rahma has been charged with incitement, stone-throwing and possession of arms, which he has said were spent cartridges and tear-gas grenades used by Israeli forces to disperse protesters.

Protest organisers say Israel has arrested 32 people from the West Bank village of Bilin in the past six months and 94 from the neighbouring village of Nilin in the past 18 months. Most have since been released.

Israel says the barrier helps prevent attacks against its citizens, but Palestinians say the fences, walls and closed roads snaking across the West Bank are aimed at snatching land that should be part of their promised state.