From Ha'Aretz:
Hamas operatives in the West Bank have experimented with adding toxic chemicals to their bombs, security sources told Haaretz Monday.
The organization also is amassing large stocks of explosives so operatives will be ready to launch attacks immediately should its leadership decide to end the security "lull," the sources added.
Currently, Hamas' West Bank cells are focusing mainly on buying arms, training operatives, setting up explosives factories and conducting experiments. However, a few cells - mainly in the southern West Bank, around Hebron and Bethlehem - are continuing to carry out small-scale attacks. These cells are only loosely connected to the organization's leadership in Damascus and Gaza, and as long as they keep a relatively low profile and do not claim responsibility for their attacks in Hamas' name, the leadership does not interfere. One such cell was arrested early this year after murdering six Israeli civilians near Gush Etzion and Hebron.
In Gaza, Hamas operatives often assist attacks carried out by Islamic Jihad and the Popular Resistance Committees. The rockets fired at Sderot last week, for instance, were made by Hamas, and "rebellious" members of the organization helped launch them. The Shin Bet security service also accused senior Hamas operatives of having helped the Popular Resistance Committees prepare a attack in April at the Karni crossing between Gaza and Israel. That plan was foiled by PA security personnel.
There is also one type of attack to which Hamas' leadership has given its unequivocal blessing: attempts to kidnap Israeli soldiers or civilians for use in negotiations over the release of Palestinian prisoners in Israel.
The Shin Bet and police arrested a senior Hamas operative in Ramallah two weeks ago who was responsible for planning several "mega-attacks." The arrest was made public Monday.
Ibrahim Hamed heads Hamas' military wing in the West Bank. His planned attacks included attempts to blow up railway tracks and an attempted bombing of the Pi Glilot gas storage facility.