Dhaka, March 18 (IANS): Bangladesh ex-Prime Minister Khaleda Zia's 20- party opposition alliance announced on Tuesday an extension of its ongoing 72-hour nationwide strike in Bangladesh till Friday morning, demanding the safe return of a spokesperson.

Khaleda Zia's Bangladesh Nationalist Party (BNP) spokesperson Barkat Ullah Bulu made the announcement at a press release, demanding necessary steps for getting back BNP Joint Secretary General Salahuddin Ahmed, Xinhua reported.

Ahmed's family alleged that some plainclothes men, who showed identity cards of the detective branch of Bangladesh police had picked up him from a house in Dhaka on March 10.

However, police authorities denied the allegation of detaining Ahmed who had recently been made BNP spokesperosn.

Khaleda Zia on Tuesday urged the government to bring Salahuddin Ahmed back to his family or present him before court immediately.

Hasina Ahmed , wife of missing BNP leader, also urged the government to take necessary steps for getting back her husband who was assigned to brief media about anti-government programs including the strike.

The BNP and its allies declared on Saturday a 72-hour road, rail and waterway strike from Sunday morning amid its ongoing blockade campaign.

The opposition alliance has been observing the blockade across the country since January 5, demanding fresh elections under a non-party caretaker government system.