By Karolos Grohmann

BERLIN (Reuters) – Borussia Dortmund will look to move within striking distance of Bundesliga leaders Bayern Munich when they travel to Hamburg SV on Friday amid heightened security at the stadium following the Paris attacks last week and a bomb scare that forced the cancellation of a Germany friendly this week.

Bundesliga clubs are boosting their security arrangements this weekend after attacks in the French capital left 129 people dead and hundreds injured.

A bomb scare only two hours before Germany were due to play the Netherlands in Hanover on Tuesday — a game that German Chancellor Angela Merkel was planning to attend — further increased security concerns among Germans.

Clubs are urging fans to turn up early, as tighter checks inside and outside stadiums are expected to lead to delays.

On the playing front, Dortmund will be looking for a fifth straight league win that would take them to within two points of undefeated champions Bayern, who are in action at Schalke 04 on Saturday. Bayern have 34 points and second-placed Dortmund 29.

Their coach, Thomas Tuchel, hopes to have Marco Reus back from injury after the attacking midfielder made a faster than expected recovery from a torn muscle sustained on Nov. 5.

“Marco Reus trained really well and is now an option to start tomorrow. It is great that everything has happened so quickly (regarding his recovery),” Tuchel told reporters on Thursday.

“I expect that we will pick up where we left off before the break for international matches regarding our alertness and our hunger on the pitch,” he said. Dortmund won their last seven matches in all competitions before the break earlier this month.

With Gonzalo Castro, Shinji Kagawa and Henrikh Mkhitaryan all in fine form, Tuchel has the luxury of choice in his midfield for the game at Hamburg, where Dortmund have won just once in the last nine years.

The hosts, on the other hand, have won only one of their last six games in all competitions.

Bayern travel to Schalke a day later having made the best ever start to a Bundesliga season, with 11 wins and a draw from their 12 matches so far.

“I’ll stick to the old adage that we have no chance whatsoever and we want to use it,” Schalke’s Aogo said. “Bayern are currently in a form where it is very difficult to beat them, either at home or away. But we will still try to take this chance, that no one outside Schalke believes we have, and make the most of it.”

Third-placed VfL Wolfsburg, who have 21 points, one ahead of Hertha Berlin and Schalke, host struggling Werder Bremen.

(Reporting by Karolos Grohmann,; Editing by Neville Dalton)