Hamas and Fatah carried out tit-for-tat arrests yesterday after deadly Gaza bomb attacks fuelled tension between the Palestinian factions. In the West Bank, security forces loyal to Palestinian President Mahmoud Abbas detained 20 Hamas activists in the city of Jenin. They netted 15 more in similar raids in Tulkarm.

A security official in Jenin said the Islamist detainees would be interrogated about arms caches and militant activities. The arrests appeared to be a response to a crackdown in the Hamas-controlled Gaza Strip, where the Islamist group rounded up more than 160 Fatah men after one of three bomb blasts killed five Hamas militants and a girl on Friday.

Hamas blamed the attacks on Fatah, which denied involvement. The flare-up between the rival groups is one of the gravest since Hamas seized control of Gaza from Abbas a year ago. Abbas, whose Fatah faction is stronger in the West Bank, said in Cairo yesterday that he and Egyptian President Hosni Mubarak had agreed to hold an intra-Palestinian dialogue to which Egypt would issue invitations within a few days.

An Egyptian-brokered truce between Israel and Hamas in the Gaza Strip took effect last month. It calls on Hamas to halt rocket fire in return for Israel gradually easing its embargo of the impoverished coastal territory. The ceasefire does not apply in the West Bank, where Israeli raids against militants have sometimes led to reprisal rocket attacks from Gaza on southern Israeli towns.

Israeli troops killed a Hamas militant, Shihab al-Natsheh, in the West Bank city of Hebron on Sunday. The Islamist group?s armed wing, the Izz el-Deen al-Qassam Brigade, vowed a «swift and painful» revenge.