The socialist and liberal trades unions are keeping their members out. Local transport company staff affiliated to the Christian union are expected back at work.
Public transport services operated by the MIVB have been disrupted since the incident on Saturday.
All metro lines should now be running normally.
Greater disruption persists on bus and tram routes. Services are only operating on four of the capital's eighteen tram routes.Trams are operating on lines 3 (good service), 4, 39, 44 and 82 (all three patchy).
Eight bus lines were running at one point this morning. Now only lines 12 and 95 are operating normally. There's a limited service on lines 13, 14, 63 and 87. No services expected on lines 13, 14 and 87 after 5:30 PM. The company expects little change before this afternoon's shift change.
Up to date information is available in English on the transport company's website mivb.be.
The socialist union is manning a picket line at the Haren bus depot. Similar protests in Schaarbeek and Molenbeek have been lifted. The union rank and file are worried that the impressive list of extra security measures announced on Monday night will never be fully implemented.
The liberal union is backing the protest, but will not picket any of the bus depots. Liberal trades unionist Kris Eckers: "People who want to work should be able to do so." Mr Eckers conceded that lines of communication between the union leadership and its rank and file were experiencing difficulties.
Not all unions agree with the strike. On Tuesday evening the Christian union decided in favour of a back-to-work, albeit under certain conditions. The unions want talks with the management to discuss the implementation of the extra security measures. The union has also given notification of strike action. This means that the union can call a strike if the talks spin out.
Until Monday night the protest had the support of the MIVB management. This is now no longer the case turning the protest into strike action. As a result of the strike Tuesday's evening rush hour proceeded in utter chaos.
Services of the Flemish and Walloon local transport companies De Lijn and TEC continue to operate normally in Brussels.
Public transport across Belgium will come to a halt on Thursday afternoon. The stoppage is expected around 2:30 PM and coincides with the funeral of the Brussels bus inspector who was killed at the weekend.
The funeral starts at 2 PM at Schaarbeek Mosque. Belgian trades unionists are staging the stoppage as a mark of respect. The idea is for all trams, buses and trains to stop for several minutes to a quarter of an hour around 2:30 on Thursday. MIVB staff wishing to attend the funeral are free to do so.