The offices belonged to the Islamic Charity Association, which was outlawed in June 2002 because of its support to families of bombers and those arrested by Israel.
The Israeli occupation army said it sealed the main zakat committee in the small town of Dura, 10km southwest of Hebron, and the village of Bani Naim, just east of the southern West Bank city.
Zakat is the obligatory alms required of Muslims, calculated as a percentage of a person's income.
Locals said Israeli soldiers, equipped with huge welding machines, sealed the premises of the two committees without informing their officials.
Both committees operated under the supervision of the Palestinian Authority's (PA) ministry of waqf (Islamic endowment) and Islamic affairs.
According to ministry officials, zakat committees in the West Bank carry out vital charitable works such as helping families in distress, helping poor college students with tuition and giving food to families which have lost their breadwinners.
"We are helping poor people, needy people ... we are doing what the apparatus of a state is supposed to do, but look what we get in return from the Israelis"
Dura zakat committee president
The charities, through a network of low-cost clinics and medical centres, also provide inexpensive or free medical services to tens of thousands of Palestinians, hard-hit by draconian punitive Israeli measures.
The Israeli army accuses the charities of being affiliated to Hamas and helping families considered Hamas sympathisers.
An Israeli army spokesperson described the charities as "an integral part of Hamas' social infrastructure".
Officials said the charity offices channelled funds to the "terror infrastructure" in the Hebron area.
But the Dura zakat committee president, Fathi Amr, denied the charges.
Feeding and helping
"We are helping poor people, needy people, orphans, widows, children who go to school in the morning without taking a decent breakfast. We are doing what the apparatus of a state is supposed to do, but look what we get in return from the Israelis," he said.
He told Aljazeera.net his committee "never indulges in any illegal activities".
"This is unless feeding and helping the poor and clothing the orphans are illegal activities ... everything is possible in this age of the 'war on terror'," he said.
Another official at the Dura zakat committee, who asked for anonymity, told Aljazeera.net: "They can't bear watching us walking in the streets smiling, they hope that we would crawl at their feet begging for mercy.
"But we don't and we won't. This is why they are so mad at us and are now venting their frustration on these charities."