The Egyptian Organisation for Human Rights (EOHR) said police holding voters back at one polling station in Kafr El-Sheikh on Thursday shot dead an opposition supporter, the third death during the elections.
EOHR said Gomaa Saad el-Ziftawi, a supporter of Hamdin Sabahi, a leftist politician, died of gunshot wounds at Baltim in the Nile Delta, north of Cairo.
A statement by the independent group said: "He was killed after security forces fired live ammunition and teargas canisters at him, and tens of voters were wounded." It named 14 injured.
The Muslim Brotherhood has increased its seats in the chamber more than fivefold in voting so far, exceeding the expectations of its own leadership and posing the strongest challenge to the ruling National Democratic Party (NDP).
Riot police surrounded polling stations in the Nile Delta and let only a trickle of voters through their lines. Voters clashed with security forces, which used teargas in several places, witnesses said.
Essam el-Erian, a leading Brotherhood member, said attempts to stop people voting for his group were more determined than in previous voting days. He said about 730 Brotherhood activists have been arrested in the last three days to weaken its chances.
Police let only a trickle of voters
through to the polling stations
Sayed Ibrahim, a Brotherhood supporter, said outside a polling station in the Kafr El-Sheikh town of Dessouk: "The police plan is to tire out voters so that they go home. Everyone here is going to vote Brotherhood."
The voting process is theoretically under judicial supervision, but the judges in charge cannot impose their will beyond the confines of the polling stations.
One judiciary official in Bassat, north of Cairo, said: "I know what they (the riot police) are doing but there's nothing I can do about it." The official asked not to be named.
The Brotherhood, which had 15 seats in the outgoing parliament, has won 76 of 444 elected places so far. The authorities restricted voting in the last stage of the poll, but the Brotherhood still won 42 seats.
Voting went on peacefully and unimpeded in some places on Thursday, including Sohag province, south of Cairo.
The NDP has boosted its seats total by readmitting winners who broke party lines to stand as independents against officially endorsed party candidates. The ruling party has 214 seats so far, state media reported on Thursday.
The final stage, which is spread over two days, will decide 136 seats. The Brotherhood, which is officially banned, is contesting only 49 places as part of its strategy not to provoke the authorities. Islamist candidates stand as independents.
The Aljazeera satellite channel said security forces detained its crew covering the election in Kafr El-Sheikh for half-an-hour and destroyed their tape.
"I know what they (the riot police) are doing but there's nothing I can do about it"
Unnamed judiciary official
Police also held Amil Khan, a correstpondent for Reuters, in Sandoub on the grounds that they needed to check his identity.
Police detained and harassed journalists and confiscated their equipment in the previous stage of voting. At least one reporter was attacked by police.
Voting has so far been less violent than in the last elections in 2000, when 10 people were killed.
Run-offs between the top two candidates will be held on 7 December for seats where no candidate wins a clear majority.