The Dhaka police on Saturday sought an extension of a British national's remand by another 10 day over his suspected involvement in the July 1 terror attack at a cafe in the Bangladeshi capital, a senior officer said.Hasnat Karim, 47, a former teacher of the North South University, and Tahmid Hasib, 22, a student at the University of Toronto witnessed the bloody carnage in the Holey Artisan Bakery and O'Kitchen Restaurant last month. They were arrested on the night of August 3 in Dhaka, the Daily Star reported.Hasnat has now been implicated in the attack, the Dhaka Tribune quoted Monirul Islam, head of the counter-terrorism unit as saying.He said the police on Saturday also filed another petition to interrogate Tahmid for another seven days. However, Tahmid was not yet arrested for the attack.On August 4, the two suspects were sent to an 8-day remand, reports the Dhaka Tribune.The two were among the 32 hostages rescued from the cafe, where the attackers killed 22 people, including 18 foreigners. Neither of the two were seen in public since the end of the 12-hour siege when commandos stormed the cafe on the morning of July 2, police said.